Patent Publication Number: US-2010114158-A1

Title: Delivery assembly, delivery tip, and method of using same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/100,781 filed Sep. 26, 2008, entitled “Delivery Assembly, Delivery Tip, and Method of Using Same” by Paul Hattan, Jason Gerold and John O. White the entire contents of which is specifically incorporated herein by reference without disclaimer. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to multi-component spray delivery devices, kits, and methods. 
     2. Description of the Related Art 
     Current applicators for, e.g., two-component delivery systems, particularly for use with bioadhesives are simple, minimalist products that are little more than an oversized syringe. Unfortunately, manual actuation of the dispensing mechanism in existing applicators often dispenses uneven amounts of liquids, particularly over a short time period. 
     Many scientific and industrial applications require a well-atomized liquid spray. Liquid atomization is most readily achieved by shearing the liquid with a gas at or before the spray discharge (air-assist atomization; air brushes). In some applications, however, the introduction of air is undesirable or impractical. In such cases, atomization is achieved by liquid-liquid shearing caused by velocity gradients near the discharge orifice. Existing commercial spray nozzles utilize radial fluid channels to direct fluid from an upstream, outer annulus towards the centrally located discharge orifice. To induce rotation and subsequent shearing and atomization, the feed channels on existing commercial spray nozzles are offset from center, or may be curved in a swirl pattern, and/or may include curved guide vanes present near the orifice. 
     Several scientific, industrial and medical applications require the spray of a two-component adhesive. In these applications, the component liquids are typically mixed within the spray nozzle then discharged together. The time between mixing and discharge must be shorter than the gel time for the mixed components or set time of the adhesive. Otherwise, gelling will occur with the nozzle, creating a clog. In the case of rapidly gelling bioadhesives, such as those designed for vascular sealing, gelling can occur almost immediately when the two component liquids are mixed. Existing applicator designs have significant empty space between the liquid feed tubes and the mixing/discharge features of the nozzle. This empty space creates opportunities for fluid recirculation and increases residence time of the fluids in the nozzle. 
     Existing airless atomized liquid spray nozzles and nozzle tips use a two channel swirl design and a two-piece insert/shell construction or a three-channel, offset-center design with a plastic shell and elastomeric tip. Uneven fluid feed channels cause problems in maintaining separation of a two-component fluid input upstream of the mixing cavity. In two-component spray applications, early mixing of the two components can cause premature gelling/solidification of the material, which can then clog the feed channels or discharge orifice. In a two or three channel design, which are both commonly available, both liquid components flow through each channel, introducing clogging potential. Moreover, these two and three channel designs require complex manufacturing methods. 
     SUMMARY OF THE INVENTION 
     Embodiments of a delivery device, a kit comprising the delivery device, and methods of using the same are presented. In one embodiment, the delivery device includes a syringe assembly defining two or more reservoirs each configured to hold a dispensable material. Additionally, the delivery device may include a delivery tip. The delivery tip may have an inlet, an outlet, a central flow-restricting portion, and one or more channels adjacent to the central flow-restricting portion that provide fluid communication between the inlet and the outlet, the one or more channels including a section that tapers inwardly toward the outlet. In one embodiment where the delivery device is configured such that if the two or more reservoirs hold dispensable material then the syringe assembly can be actuated to dispense the dispensable material from the two or more reservoirs substantially simultaneously into the inlet. 
     In another embodiment, the delivery tip may have an inlet, a central flow-restricting portion, a distal portion comprising a nozzle that includes an outlet, and one or more channels adjacent to the central flow-restricting portion that provide fluid communication between the inlet and the outlet. In such an embodiment, the delivery tip may be characterized by a central axis running from the inlet to the outlet. The nozzle may include a section that tapers outwardly and away from the outlet along the central axis. In such an embodiment, the delivery device is configured such that if the two or more reservoirs hold dispensable material then the syringe assembly can be actuated to dispense the dispensable material from the two or more reservoirs substantially simultaneously into the inlet. 
     In one embodiment, the delivery tip includes a conduit portion having an inlet and a distal portion comprising a nozzle that includes an outlet. The delivery tip may also include a central flow-restricting portion disposed inside the conduit portion. The delivery tip may further comprise one or more channels adjacent to the central flow-restricting portion that provide fluid communication between the inlet and the outlet. In such an embodiment, the delivery tip may be characterized by a central axis running from the inlet to the outlet, and the nozzle including a section that tapers outwardly and away from the outlet along the central axis. 
     In another embodiment, the delivery tip may include one or more channels adjacent to the central flow-restricting portion that provide fluid communication between the inlet and the outlet. The one or more channels may include a section that tapers inwardly toward the outlet. 
     In a further embodiment of the delivery device, the one or more channels include multiple sections, each of which converges at an angle less than 90 degrees. Additionally, the one or more channels may include three sections, each of which converges at an angle less than 90 degrees. In one embodiment, the one or more channels include a swirl chamber inside the delivery tip and adjacent to the outlet. The delivery tip may characterized by a central axis running from the inlet to the outlet, and the swirl chamber may be configured such that it intersects a plane that is perpendicular to the central axis in a profile having three sides each defined by a line, the three lines forming a substantially equilateral triangle. 
     In one embodiment, the delivery tip may include a conduit, and the central flow-restricting portion may be coupled to but not integral with the conduit. The one or more channels may comprise at least some recesses in the central flow-restricting portion. In another embodiment, the one or more channels comprise at least some recesses in the conduit. 
     In one embodiment, the delivery device includes an attachment mechanism configured to couple the delivery tip to the syringe assembly. For example, the attachment mechanism may include one or more flanges that are integral with the delivery tip. In another embodiment, the attachment mechanism may include one or more threaded portions that are integral with the delivery tip. 
     A kit is also presented. In one embodiment, the kit includes an adhesive compound comprising a plurality of dispensable components. Additionally, the kit may include a syringe assembly defining two or more reservoirs each configured to hold one of the dispensable components. The kit may also include a delivery tip. The delivery tip may have an inlet, an outlet, a central flow-restricting portion, and one or more channels adjacent to the central flow-restricting portion that provide fluid communication between the inlet and the outlet. In one embodiment, the one or more channels include a section that tapers inwardly toward the outlet. 
     In one embodiment, the delivery tip may include an inlet, a central flow-restricting portion, a distal portion comprising a nozzle that includes an outlet, and one or more channels adjacent to the central flow-restricting portion that provide fluid communication between the inlet and the outlet. In such an embodiment, the delivery tip may be characterized by a central axis running from the inlet to the outlet. The nozzle may have a section that tapers outwardly and away from the outlet along the central axis. 
     Joinder references used in this disclosure (attached, coupled, connected) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other. In particular, the term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. 
     The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. 
     The term “substantially” and its variations are defined as being largely but not necessarily wholly what is specified as understood by one of ordinary skill in the art, and in one non-limiting embodiment “substantially” refers to ranges within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5% of what is specified. 
     The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed. 
     Other features and associated advantages will become apparent with reference to the following detailed description of specific embodiments in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers. The figures are drawn to scale (unless otherwise noted), meaning the sizes of the depicted elements are accurate relative to each other for at least the set of embodiments depicted in the figures. 
         FIG. 1  shows a perspective view of one embodiment of a delivery device; 
         FIG. 2  shows an exploded view of one embodiment of a delivery device; 
         FIG. 3  shows a side cross-section view of one embodiment of a delivery device; 
         FIG. 4  shows a perspective view of one embodiment of an applicator according to one embodiment of a delivery device; 
         FIG. 5  shows a rear view of one embodiment of an applicator according to one embodiment of a delivery device; 
         FIG. 6  shows a perspective exploded view of one embodiment of an applicator and delivery tip assembly; 
         FIG. 7  shows a perspective view of one embodiment of an assembled applicator and delivery tip; 
         FIG. 8  shows a side cross-section view of one embodiment of an assembled applicator and delivery tip; 
         FIG. 9  shows a perspective view of one embodiment of a conduit portion of a delivery tip; 
         FIG. 10  shows a side cross-section view of one embodiment of a conduit portion of a delivery tip; 
         FIG. 11  shows a perspective view of one embodiment of a conduit portion of a delivery tip; 
         FIG. 12  shows a perspective ghosted view of one embodiment of a delivery tip; 
         FIG. 13  shows a side ghosted view of another embodiment of a delivery tip; 
         FIG. 14  shows a distal ghosted view of the embodiment of a delivery tip described in accordance with the embodiment of  FIG. 13 ; 
         FIG. 15  shows a distal ghosted view of the embodiment of a delivery tip described in accordance with the embodiment of  FIG. 12 ; 
         FIG. 16  shows a perspective view of one embodiment of the central flow-restricting portion of the embodiment of the delivery tip described according to  FIG. 12 ; 
         FIG. 17  shows a distal view of one embodiment of the central flow-restricting portion of the embodiment of the delivery tip described according to  FIG. 12 ; 
         FIG. 18  shows a perspective view of one embodiment of the central flow-restricting portion of the embodiment of the delivery tip described according to  FIG. 12 ; 
         FIG. 19  shows a perspective exploded view of another embodiment of an applicator and delivery tip; 
         FIG. 20  shows a perspective ghosted view of another embodiment of a delivery tip; 
         FIG. 21  shows a proximal perspective view of the embodiment of a delivery tip described in  FIG. 20 ; 
         FIG. 22  shows a distal perspective view of another embodiment of a flow-restricting portion of a delivery tip; 
         FIG. 23  shows a proximal perspective view of the embodiment of a flow-restricting portion of the delivery tip described in  FIG. 22 ; 
         FIG. 24  shows one embodiment of a kit comprising a delivery device according to one embodiment; 
         FIG. 25  shows a perspective view of one embodiment of an insertion tool for inserting a central flow-restricting portion of a delivery tip into a conduit portion of a delivery tip; and 
         FIG. 26  shows a side view of one embodiment of an insertion tool inserting a central flow-restricting portion of a delivery tip into a conduit portion of a delivery tip. 
     
    
    
     DETAILED DESCRIPTION 
     Various features and advantageous details are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well known starting materials, processing techniques, components, and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments of the invention, are given by way of illustration only, and not by way of limitation. Various substitutions, modifications, additions, and/or rearrangements within the spirit and/or scope of the underlying inventive concept as defined by the claims will become apparent to those skilled in the art from this disclosure. 
       FIGS. 1-3  illustrate one embodiment of a delivery device  100 . In the depicted embodiment, the delivery device  100  includes a syringe assembly  102  and a delivery tip  104 . The delivery device  100  may also include an actuator  110  and an applicator housing  112 . 
     In a general embodiment, the syringe assembly  102  may include a plurality of reservoirs. The reservoirs may each be configured to hold a dispensable material. For example, the reservoirs may include syringes  108  and  109 . In certain embodiments, the syringe assembly  102  may also include a syringe holder  106 . Alternatively, the syringe assembly may include a syringe housing (not shown). As shown in  FIG. 1 , the syringe holder  106  may provide mechanical support for the syringes  108  and  109 . In a further embodiment, the syringe holder  106  may include a locking or attaching mechanism, such as a clamp, for securing the syringes  108  and  109  to the syringe holder  106 . 
     The actuator  110  may be coupled to the syringes  108  and  109 . In one embodiment, if the syringes  108  and  109  hold dispensable material, then the syringe assembly  102  can be actuated by the actuator  110  to dispense the dispensable material from the syringes  108  and  109  substantially simultaneously. For example, if the syringe assembly  102  includes two syringes  108  and  109 , as shown in  FIGS. 1 and 2 , the actuator  110  may cause both syringes  108  and  109  to dispense a dispensable material at substantially the same time. In a particular example, the dispensable material may be an adhesive compound having multiple dispensable components that, when mixed, form the adhesive. In a particular embodiment, a first syringe  108  may hold a first dispensable component and a second syringe  109  may hold a second dispensable component. The actuator  110  may cause both the first and the second dispensable components to be dispensed from the syringes  108  and  109  at substantially the same time. 
     To further facilitate dispensing of the dispensable material, and the like, the syringe assembly  102  may also include one or more handles  114 . The handles  114  may include grips, loops, flanges, ribs, or the like. In certain embodiments, the handles  114  may be integrated with the actuator  110  to facilitate dispensing the dispensable material. 
     As shown in  FIG. 3 , the applicator housing  112  may house an applicator  302 . The applicator  302  may couple the syringe assembly  102  to the delivery tip  104 . In particular, the applicator  302  may provide fluid communication between the syringes  108  and  109  and the delivery tip  104 . As illustrated in  FIG. 4 , the applicator  302  may include a first feed tube  410  having a first feed channel  402  and a second feed tube  414  having a second feed channel  404 . The first feed channel  402  may couple a first syringe  108  to the delivery tip  104  and the second feed channel may couple a second syringe  109  to the delivery tip. 
     In a particular configuration as shown in  FIG. 4 , the applicator  302  may include a ‘Y’ shaped structure. In certain embodiments, the first feed channel  402  and the second feed channel  404  may converge to a singe channel within the body  410  of the applicator  302 . Alternatively, the first feed channel  402  and the second feed channel may remain separated within the body  410  of the applicator  302 . As illustrated in  FIG. 5 , the applicator  302  may include a plurality of inlets  504  each coupling the applicator  302  to a reservoir, such as a syringe  108  or  109 . The applicator  302  may further comprise structural support, such as a bridge  502  supporting the first feed tube  412  and the second feed tube  414 . 
     The applicator  302  may also include a first attachment member  408  configured for use in an attachment mechanism to a mating second attachment member  408 . In one embodiment, the first attachment member  408  may include an annular collar. The annular collar may provide mechanical support for the deliver tip. In a further embodiment, the first attachment member  408  may include a portion of a locking device, such as a luer lock. In yet another embodiment, the first attachment member  408  may include a threaded collar configured to receive mating threads. 
       FIG. 6  illustrates one particular embodiment of an attachment mechanism. In the depicted embodiment, a conduit portion  602  of the delivery tip  104  and the applicator  302  include luer lock components for attaching the delivery tip  104  to the applicator  302 . Additionally,  FIG. 6  illustrates an exploded view of one embodiment of a delivery tip  104 . As shown, the delivery tip  104  may include a conduit portion  602  and a central flow-restricting portion  604 . The central flow-restricting portion  604  may be inserted into the conduit portion, and the conduit portion  602  may be attached to the applicator  302  or to the syringes  108  and  109  through alternative coupling means, such as tubes, couplers, or the like.  FIGS. 7 and 8  illustrate one embodiment of the assembled conduit portion  602 , central flow-restricting portion  604  and applicator  302 . 
       FIG. 9  illustrates a further embodiment of the conduit portion  602  of the delivery tip. In one embodiment, the conduit portion  602  includes a nozzle  902 . The conduit portion  602  may also include one or more flanges  904  for mating with the attachment member  408 . For example, the flanges  904  may mate with an annular collar of a luer lock assembly. 
       FIG. 10  describes the conduit portion  602  in greater detail. In one embodiment, the conduit portion  602  may include an inlet  1002  and a distal portion comprising a nozzle  902  that includes an outlet  1004 . In such an embodiment, the delivery tip  104  may be characterized by a central axis  1006  running from the inlet  1002  to the outlet  1004 . The nozzle  902  may include a section  1008  that tapers outwardly and away from the outlet  1004  along the central axis  1006 .  FIG. 11  further illustrates the inlet  1002  and the flange  904 . 
       FIG. 12  shows one embodiment of an assembled delivery tip  104 . The delivery tip  104  may include an inlet  1002 , a central flow-restricting portion  604 , a distal portion comprising a nozzle  902  that includes an outlet  1004 , and one or more channels  1204  adjacent to the central flow-restricting portion  604  that provide fluid communication between the inlet  1002  and the outlet  1004 . In such an embodiment, the delivery device is configured such that if the two or more reservoirs  108  and  109  hold dispensable material then the syringe assembly  102  can be actuated to dispense the dispensable material from the two or more reservoirs  108  and  109  substantially simultaneously into the inlet  1002 . 
     As illustrated in  FIGS. 12 and 13 , the delivery tip  104  may include a conduit portion  602  and a central flow-restricting portion  604 . In one embodiment, the conduit portion  602  and the central flow-restricting portion  604  may be coupled but not integral. In an alternative embodiment, the central flow-restricting portion  604  may be integrally formed within the conduit portion  602 . The one or more channels  1204  may comprise at least some recesses in the central flow-restricting portion  604 . In another embodiment, the one or more channels  1204  comprise at least some recesses in the conduit  602 . The recesses may be formed by ridges  1202  formed on the central flow-restricting portion  604  as shown in  FIG. 12 . 
     Alternatively, as shown in  FIG. 13 , the ridges  1202  may be formed on the conduit portion  602 . In such an embodiment, the ridges  1202  may be further configured to retain the central flow-restricting portion  604  within the conduit portion  602 . To facilitate insertion of the central flow-restricting portion  604 , the ridges  1202  may include a tapered portion  1302  as illustrated. The tapered portion  1302  may additionally direct the dispensable material into the channels  1204 . As shown in  FIGS. 12 and 13 , the channels  1204  may run adjacent to the central flow-restricting portion  604  and provide fluid communication between the inlet  1002  and the outlet  1004 . 
     In a further embodiment, illustrated in  FIG. 14 , the one or more channels  1204  may include a section  1402  that tapers inwardly toward the outlet  1004 . In a further embodiment, the one or more channels  1204  include multiple sections  1402 , each of which converges at an angle less than 90 degrees. For example, as illustrated in  FIG. 14 , the one or more channels  1204  may include three sections  1402 , each of which converges at an angle less than 90 degrees. In an alternative embodiment, illustrated in  FIG. 15 , the delivery tip  104  may include four channels  1204 , each having a portion  1402  that converges at an angle less that 90 degrees. In one embodiment, the portions  1402  of the channels  1204  that converge may be formed between raised portions  1404  of the conduit portion  602 . Alternatively, the raised portions  1404  may be formed on the central flow-restricting portion  604  as illustrated in  FIGS. 15-18 . 
     In one embodiment, the one or more channels  1204  include a swirl chamber  1406  inside the delivery tip  104  and adjacent to the outlet  1004 . The delivery tip  104  may be characterized by a central axis  1006  running from the inlet  1002  to the outlet  1004 , and the swirl chamber  1406  may be configured such that it intersects a plane that is perpendicular to the central axis  1006  in a profile having three sides each defined by a line, the three lines forming a substantially equilateral triangle as illustrated in  FIG. 14 . 
       FIG. 19  illustrates a further embodiment of an assembly of the conduit  602 , the central flow-restricting portion  604 , and the applicator  302 . In the described embodiment, the first feed channel  402  and the second feed channel  404  may include hoses or pipes running through the body of the applicator  302 . Additionally, the attachment mechanism may include a threaded portion  1902  of the conduit portion  602  and a mating threaded portion (not shown) on the applicator  302 . The threaded portion  1902  may include one or more threads  2002  as illustrated in  FIG. 20 . 
     In this embodiment, the central flow-restricting portion  602  may also be inserted into the conduit portion  602  as shown in  FIG. 20 . Various configurations of the channels  1204  running adjacent to the central flow-restricting portion  604  may be formed, depending upon the geometry of the central flow-restricting portion  604  and the conduit portion  602 . For example, in  FIG. 21 , the channels  1204  may have a substantially circular cross-section. Alternatively, the channels may have a substantially rectangular, square, oval, or other geometrically shaped cross-section. 
     Indeed, as illustrated in  FIGS. 22 and 23 , the geometry of the central flow-restricting portion  604  may be selected to enhance certain flow characteristics, including flow-rate, clog susceptibility, fluid rotation, swirl velocity, and the like. For example, the channel may converge as it nears the outlet  1004 . 
     The viscosity of the dispensable material may affect the spray performance. In one embodiment, the viscosity of the dispensable may be within a predetermined range of the viscosity of water at room-temperature (˜1 cP). 
       FIG. 24  shows one embodiment of a kit  2400  comprising a delivery device  100  according to one embodiment. The kit  2400  may include an adhesive compound comprising a plurality of dispensable components. The dispensable components may be stored in separate containers  2402 ,  2404 . For example, a first container  2402  may hold a first dispensable component, and a second container  2404  may hold a second dispensable component. In one embodiment, the containers  2402 ,  2404  may hold the dispensable components during shipment. In such an embodiment, the two or more reservoirs  108  and  109  may be filled with the dispensable components from the containers  2402 ,  2404 . Alternatively, the containers  2402 ,  2404  may be eliminated, and the dispensable components may be shipped directly in the reservoirs  108  and  109 . 
     The kit  2400  may include a syringe assembly  102 , and an applicator housing  112 . The kit  2400  may also include an applicator  302 . In a further embodiment, the kit may include a delivery tip  104 , comprising a conduit portion  602  and a central flow-restricting portion  604 . The kit  2400  may be shipped in a housing, box, or other suitable packaging. In certain embodiments, the components and packaging of the kit  2400  may be sterilized and hermetically sealed to avoid contamination. Thus, the kit  2400  may be ready for use during surgery without the need for additional sterilization of the components of the kit  2400 . 
       FIGS. 25-26  illustrate one embodiment of an insertion tool  2500  for inserting the central flow-restricting portion  604  into the conduit portion  602  of the delivery tip  104 . In one embodiment, the insertion tool  2500  may include a ram-rod  2504 . In a further embodiment, the insertion tool  2500  may include one or more alignment posts  2502  for aligning the insertion tool in a press (not shown). As shown in  FIG. 26 , the central flow-flow restricting portion  604  may be inserted into the conduit portion  602 . The ram-rod  2504  may also be inserted into the conduit portion  602 . In a further embodiment, pressure may be applied to a top surface  2602  of the insertion tool  2500  until the central flow-restricting portion  604  has been inserted into the conduit portion  604  to within a predetermined range of a predetermined depth. 
     In some embodiments, the delivery device  100  described herein consists of components for preparation of a synthetic polymeric adhesive/sealant, and an applicator for delivery of the sealant to a target site, such as a surgical site or wound. The sealant comprises two solutions: a polyethylene glycol (PEG) solution and a cross-linking solution. When mixed together, the precursors rapidly cross-link to form the hydrogel sealant. The mixing of the precursors is accomplished as the materials exit the delivery tip  104  of the delivery device  100 . 
     In one embodiment, a kit is provided that includes the delivery device  100 , including syringes  108  and  109 , adhesive components and instructions for the application of the adhesive material. Kits may further comprise any other device, material, or component useful for any medical procedure in which the delivery device  100  is employed. Such additional devices, materials, and components include, but are not limited to, drugs (e.g., anesthetics, coagulants, vasoconstrictors), meshes, sutures, dressings, cutting devices, hemostats, clamps, disinfectants, sponges, soaps, retractors, gloves, masks, gowns, syringes, needles, and the like. 
     Suitable polymeric materials useful to prepare the adhesive material include, but are not limited to, those composed of dihydroxyphenylalanine derivatives (DHP), such as 3,4-dihydroxyphenylalanine (DOPA), dopamine, 3,4-dihydroxyhydroccinamic acid (DOHA), and other catechols, and polymers of known biocompatibilities (e.g., polyethylene glycol (PEG)) and biodegradability (e.g., polycaprolactone (PCL), polylactic acid (PLA), polyglycolic acid (PGA), or various combination of the polyesters). Additionally, other DHP-modified polymers can be used. Non-limiting examples of such polymers include those described in US Pub. No. 20080247984, US Pub. No. 20030087338, US Pub. No. 20050288398, US Pub. No. 20060009550, US Pub. No. 20060241281, US Pub. No. 20070208141, US Pub. No. 20080149566, US Pub. No. 20080169059, US Pub. No. 20080171012, US Pub. No. 20080247984, US Pub. No. 20090123652, and US Pub. No. 20090163661, and U.S. Appln. Ser. Nos. 60/821,459, 11/834,651, 12/239,787, 61/100,742, 61/150,471, 61/100,781, 61/100,560, 61/100,738, 61/150,483, 61/160,479, and 61/150,464, each of which is herein incorporated by reference in its entirety. 
     The invention further provides crosslinked hydrogels derived from the compositions described herein. For example, two dihydroxyphenyl (DHPD) moieties from two separate polymer chains can be reacted to form a bond between the two DHPD moieties, e.g., catechols. Typically, this is an oxidative/radical initiated crosslinking reaction wherein oxidants/initiators such as periodates and iodates, such as NaIO 4  or KIO 4 , NaIO 3  or KIO 3  and the like, FeCl 3 , H 2 O 2 , oxygen, an inorganic base, an organic base or an enzymatic oxidase can be used. Typically, a ratio of oxidant/initiator to DHPD containing material is between about 0.2 to about 1.0 (on a molar basis) (oxidant:DHPD). In one particular embodiment, the ratio is between about 0.25 to about 0.75 and more particularly between about 0.4 to about 0.6 (e.g., 0.5). It has been found that periodate is very effective in the preparation of crosslinked hydrogels described herein. 
     A typical procedure to prepare the adhesive coating is described as follows. 
     1. Open a transfer valve between the diluent syringe  108  and the powder syringe containing polymer (not shown) using an attached luer lock transfer valve. 
     2. Transfer the diluent into polymer powder by gently depressing the plunger on the diluent syringe  108 . Mix contents back and forth between the syringes at 20-30 times, or until the solid is completely dissolved. Push contents into the diluent syringe  108 . Discard powder syringe and transfer valve. 
     3. Expel air from the diluent syringe  108 . 
     4. It is preferred that the diluent syringe  108  and crosslinker syringe  109  contain equal volumes of liquid. If fluid levels are not equal, expel fluids out of syringes until equal. 
     5. Attach the two precursor syringes  108  and  109  to the “Y”-shaped applicator  302 . 
     6. While holding syringes  108  and  109  by the barrels, seat the syringes into the syringe assembly and attach a plunger link to the plungers of both syringes  108  and  109  without dispensing precursors into the applicator. 
     7. Attach one delivery tip  104  to the end of the applicator. 
     8. Position the delivery device  100  approximately 4 cm above the target site. Apply even pressure to the center of the plunger link to dispense the precursors. To achieve best results begin application by spraying on gauze. Move applicator directly to the target site in a single motion. 
     9. Continue applying the hydrogel until a thin (approx. 1-2 mm) coating is formed. Maintain 2-3 mm margins around a suture line. Gelation will occur within a few seconds. 
     10. Excess hydrogel may be removed with scissors or mechanical disruption. Irrigation immediately after the sealant has solidified is permitted. 
     The following paragraphs enumerated consecutively from 1 through 63 provide for various aspects of the present invention. In one embodiment, in a first paragraph (1), the present invention provides a delivery device comprising: 
     a syringe assembly defining two or more reservoirs each configured to hold a dispensable material; and 
     a delivery tip having an inlet, an outlet, a central flow-restricting portion, and one or more channels adjacent the central flow-restricting portion that provide fluid communication between the inlet and the outlet, the one or more channels including a section that tapers inwardly toward the outlet; 
     where the delivery device is configured such that if the two or more reservoirs hold dispensable material then the syringe assembly can be actuated to dispense the dispensable material from the two or more reservoirs substantially simultaneously into the inlet. 
     2. The delivery device of paragraph 1, where the one or more channels include multiple sections, each of which converges at an angle less than 90 degrees. 
     3. The delivery device of paragraph 2, where the one or more channels include three sections, each of which converges at an angle less than 90 degrees. 
     4. The delivery device of paragraph 1, where the one or more channels include a swirl chamber inside the delivery tip and adjacent to the outlet. 
     5. The delivery device of paragraph 4, where the delivery tip is characterized by a central axis running from the inlet to the outlet, and the swirl chamber is configured such that it intersects a plane that is perpendicular to the central axis in a profile having three sides each defined by a line, the three lines forming a substantially equilateral triangle. 
     6. The delivery device of paragraph 1, where the delivery tip includes a conduit, and the central flow-restricting portion is coupled to but not integral with the conduit. 
     7. The delivery device of paragraph 6, where the one or more channels comprise at least some recesses in the central flow-restricting portion. 
     8. The delivery device of paragraph 6, where the one or more channels comprise at least some recesses in the conduit. 
     9. The delivery device of paragraph 1, further comprising an attachment mechanism configured to couple the delivery tip to the syringe assembly. 
     10. The delivery device of paragraph 9, where the attachment mechanism comprises one or more flanges that are integral with the delivery tip. 
     11. A delivery device comprising: 
     a syringe assembly defining two or more reservoirs each configured to hold a dispensable material; and 
     a delivery tip having an inlet, a central flow-restricting portion, a distal portion comprising a nozzle that includes an outlet, and one or more channels adjacent the central flow-restricting portion that provide fluid communication between the inlet and the outlet, the delivery tip being characterized by a central axis running from the inlet to the outlet, the nozzle including a section that tapers outwardly and away from the outlet along the central axis; 
     where the delivery device is configured such that if the two or more reservoirs hold dispensable material then the syringe assembly can be actuated to dispense the dispensable material from the two or more reservoirs substantially simultaneously into the inlet. 
     12. The delivery device of paragraph 11, where the one or more channels include multiple sections, each of which converges at an angle less than 90 degrees. 
     13. The delivery device of paragraph 12, where the one or more channels include three sections, each of which converges at an angle less than 90 degrees. 
     14. The delivery device of paragraph 11, where the one or more channels include a swirl chamber inside the delivery tip and adjacent to the outlet. 
     15. The delivery device of paragraph 14, where the delivery tip is characterized by a central axis from the inlet to the outlet, and the swirl chamber is configured such that it intersects a plane that is perpendicular to the central axis in a profile having three sides each defined by a line, the three lines forming a substantially equilateral triangle. 
     16. The delivery device of paragraph 11, where the delivery tip includes a conduit, and the central flow-restricting portion is coupled to but not integral with the conduit. 
     17. The delivery device of paragraph 16, where the one or more channels comprise at least some recesses in the central flow-restricting portion. 
     18. The delivery device of paragraph 16, where the one or more channels comprise at least some recesses in the conduit. 
     19. The delivery device of paragraph 11, further comprising an attachment mechanism configured to couple the delivery tip to the syringe assembly. 
     20. The delivery device of paragraph 19, where the attachment mechanism comprises one or more flanges that are integral with the delivery tip. 
     21. A delivery tip comprising: 
     a conduit portion having an inlet and a distal portion comprising a nozzle that includes an outlet; 
     a central flow-restricting portion disposed inside the conduit portion; and 
     one or more channels adjacent the central flow-restricting portion that provide fluid communication between the inlet and the outlet; 
     where the delivery tip is characterized by a central axis running from the inlet to the outlet, and the nozzle including a section that tapers outwardly and away from the outlet along the central axis. 
     22. The delivery tip of paragraph 21, where the central flow-restricting portion is coupled to but not integral with the conduit portion. 
     23. The delivery tip of paragraph 21, where the one or more channels include multiple sections, each of which converges at an angle less than 90 degrees. 
     24. The delivery tip of paragraph 23, where the one or more channels include three sections, each of which converges at an angle less than 90 degrees. 
     25. The delivery tip of paragraph 21, where the one or more channels include a swirl chamber inside the delivery tip and adjacent to the outlet. 
     26. The delivery tip of paragraph 25, where the delivery tip is characterized by a central axis from the inlet to the outlet, and the swirl chamber is configured such that it intersects a plane that is perpendicular to the central axis in a profile having three sides each defined by a line, the three lines forming a substantially equilateral triangle. 
     27. The delivery tip of paragraph 21, where the delivery tip includes a conduit, and the central flow-restricting portion is coupled to but not integral with the conduit. 
     28. The delivery tip of paragraph 27, where the one or more channels comprise at least some recesses in the central flow-restricting portion. 
     29. The delivery tip of paragraph 27, where the one or more channels comprise at least some recesses in the conduit. 
     30. The delivery tip of paragraph 21, further comprising an attachment mechanism configured to couple the delivery tip to the syringe assembly. 
     31. The delivery tip of paragraph 30, where the attachment mechanism comprises one or more flanges that are integral with the delivery tip. 
     32. A delivery tip comprising: 
     a conduit portion having an inlet and a distal portion comprising a nozzle that includes an outlet; 
     a central flow-restricting portion disposed inside the conduit portion; and 
     one or more channels adjacent the central flow-restricting portion that provide fluid communication between the inlet and the outlet, the one or more channels including a section that tapers inwardly toward the outlet. 
     33. The delivery tip of paragraph 32, where the central flow-restricting portion is coupled to but not integral with the conduit portion. 
     34. The delivery tip of paragraph 32, where the one or more channels include multiple sections, each of which converges at an angle less than 90 degrees. 
     35. The delivery tip of paragraph 34, where the one or more channels include three sections, each of which converges at an angle less than 90 degrees. 
     36. The delivery tip of paragraph 32, where the one or more channels include a swirl chamber inside the delivery tip and adjacent to the outlet. 
     37. The delivery tip of paragraph 36, where the delivery tip is characterized by a central axis from the inlet to the outlet, and the swirl chamber is configured such that it intersects a plane that is perpendicular to the central axis in a profile having three sides each defined by a line, the three lines forming a substantially equilateral triangle. 
     38. The delivery tip of paragraph 32, where the delivery tip includes a conduit, and the central flow-restricting portion is coupled to but not integral with the conduit. 
     39. The delivery tip of paragraph 38, where the one or more channels comprise at least some recesses in the central flow-restricting portion. 
     40. The delivery tip of paragraph 38, where the one or more channels comprise at least some recesses in the conduit. 
     41. The delivery tip of paragraph 32, further comprising an attachment mechanism configured to couple the delivery tip to the syringe assembly. 
     42. The delivery tip of paragraph 41, where the attachment mechanism comprises one or more flanges that are integral with the delivery tip. 
     43. A kit comprising: 
     an adhesive compound comprising a plurality of dispensable components; 
     a syringe assembly defining two or more reservoirs each configured to hold one of the dispensable components; and 
     a delivery tip having an inlet, an outlet, a central flow-restricting portion, and one or more channels adjacent the central flow-restricting portion that provide fluid communication between the inlet and the outlet, the one or more channels including a section that tapers inwardly toward the outlet; 
     where the delivery device is configured such that if the two or more reservoirs hold dispensable components then the syringe assembly can be actuated to dispense the dispensable components from the two or more reservoirs substantially simultaneously into the inlet. 
     44. The kit of paragraph 43, where the one or more channels include multiple sections, each of which converges at an angle less than 90 degrees. 
     45. The kit of paragraph 44, where the one or more channels include three sections, each of which converges at an angle less than 90 degrees. 
     46. The kit of paragraph 43, where the one or more channels include a swirl chamber inside the delivery tip and adjacent to the outlet. 
     47. The kit of paragraph 46, where the delivery tip is characterized by a central axis running from the inlet to the outlet, and the swirl chamber is configured such that it intersects a plane that is perpendicular to the central axis in a profile having three sides each defined by a line, the three lines forming a substantially equilateral triangle. 
     48. The kit of paragraph 43, where the delivery tip includes a conduit, and the central flow-restricting portion is coupled to but not integral with the conduit. 
     49. The kit of paragraph 48, where the one or more channels comprise at least some recesses in the central flow-restricting portion. 
     50. The kit of paragraph 48, where the one or more channels comprise at least some recesses in the conduit. 
     51. The kit of paragraph 43, further comprising an attachment mechanism configured to couple the delivery tip to the syringe assembly. 
     52. The kit of paragraph 51, where the attachment mechanism comprises one or more flanges that are integral with the delivery tip. 
     53. A kit comprising: 
     an adhesive compound comprising a plurality of dispensable components; 
     a syringe assembly defining two or more reservoirs each configured to hold a dispensable component; and 
     a delivery tip having an inlet, a central flow-restricting portion, a distal portion comprising a nozzle that includes an outlet, and one or more channels adjacent the central flow-restricting portion that provide fluid communication between the inlet and the outlet, the delivery tip being characterized by a central axis running from the inlet to the outlet, the nozzle including a section that tapers outwardly and away from the outlet along the central axis; 
     where the delivery device is configured such that if the two or more reservoirs hold dispensable component then the syringe assembly can be actuated to dispense the dispensable component from the two or more reservoirs substantially simultaneously into the inlet. 
     54. The kit of paragraph 53, where the one or more channels include multiple sections, each of which converges at an angle less than 90 degrees. 
     55. The kit of paragraph 54, where the one or more channels include three sections, each of which converges at an angle less than 90 degrees. 
     56. The kit of paragraph 53, where the one or more channels include a swirl chamber inside the delivery tip and adjacent to the outlet. 
     57. The kit of paragraph 56, where the delivery tip is characterized by a central axis running from the inlet to the outlet, and the swirl chamber is configured such that it intersects a plane that is perpendicular to the central axis in a profile having three sides each defined by a line, the three lines forming a substantially equilateral triangle. 
     58. The kit of paragraph 53, where the delivery tip includes a conduit, and the central flow-restricting portion is coupled to but not integral with the conduit. 
     59. The kit of paragraph 58, where the one or more channels comprise at least some recesses in the central flow-restricting portion. 
     60. The kit of paragraph 58, where the one or more channels comprise at least some recesses in the conduit. 
     61. The kit of paragraph 53, further comprising an attachment mechanism configured to couple the delivery tip to the syringe assembly. 
     62. The kit of paragraph 61, where the attachment mechanism comprises one or more flanges that are integral with the delivery tip. 
     63. A method to seal a surgical site or a wound comprising the step of applying an adhesive that is admixed in a delivery device comprising: 
     a syringe assembly defining a first reservoir and a second reservoir, each configured to hold a dispensable material, wherein the first reservoir contains a solution of a polymeric catechol material and the second reservoir contains a crosslinking solution of a periodate; and 
     a delivery tip having an inlet, an outlet, a central flow-restricting portion, and one or more channels adjacent the central flow-restricting portion that provide fluid communication between the inlet and the outlet, the one or more channels including a section that tapers inwardly toward the outlet; 
     where the delivery device is configured such that if the two or more reservoirs hold dispensable material then the syringe assembly can be actuated to dispense the dispensable material from the two or more reservoirs substantially simultaneously into the inlet. 
     It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Although various representative embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art having the benefit of this disclosure will recognize that numerous alterations could be made to the disclosed embodiments without departing from the spirit or scope of the inventive subject matter set forth in the claims. For example, in methodologies directly or indirectly set forth herein, various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that steps and operations may be rearranged, replaced, or eliminated and still fall within the scope of the claims. For example, as described in the figures above, various embodiments of a central flow-restricting portion  604  may be used in conjunction with various embodiments of a conduit portion  602 . In particular, the shape and configuration of the channels may be altered to modify the flow characteristics of the delivery tip  104 . For example, the present embodiments have been described with three or four channels  1204 , but more or fewer channels may be used. In particular, the delivery tip  104  may include only two channels  1204 . Alternatively, an embodiment of the delivery tip  104  may include five channels  1204 . 
     The claims are not to be interpreted as including means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.