Abstract:
A nasal insert including an antimicrobial agent is inserted into the nose to eliminate or reduce undesirable microbes in the area just inside the nose. Pads of the nasal insert can be formed from a blended polymer compound with a microbial agent. Processing of the pre-polymer results in the microbial agent being trapped in the polymer. A blowing agent or CO 2  gas can be introduced in the process after decompression, and before molding to improve attraction of liquid born microbes to the nasal insert.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a nasal insert formed of a plastic material blended with an antimicrobial agent and a method of making the nasal insert to improve attraction of microbes to the nasal insert, and allow for maximum contact of the nasal insert with the host environment. 
     2. Description of Related Art 
     Medical devices incorporating antimicrobial agents are known. U.S. Pat. No. 5,326,567 describes antimicrobial agents as chemical compositions that inhibit microbial growth or kill bacteria, fungi and other microorganisms. A liquid silver-based antimicrobial composition is formed of a stabilizing acyclic polyether polymer, silver ion and a stabilizing halide. The composition can be applied to the medical device through painting spraying or dipping to all surfaces. 
     U.S. Patent Application Publication No. 2012/0067346 describes a strip or mask for reducing spread of bacterial infections such as methicillin-resistant  staphylococcus aureus  (MRSA). The strip or mask contains an antimicrobial agent capable of being delivered to eradicate the colonization of bacteria within the nose. The strip is applied to the nose or a surgical mask is placed over the nose and mouth. In one embodiment, the strip or mask may contain a plurality of layers having a silver coating or a compound containing silver which reacts with skin or moisture to release silver to the colony in the nose. 
     It is desirable to provide an improved medical device in which all surfaces of the device include antimicrobial properties for attracting microbes, such as bacteria, and releasing antimicrobial agents for killing or inhibiting the growth of the microbes. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a nasal insert including an antimicrobial agent to create an antimicrobial device. The nasal insert is inserted into the nose to eliminate or reduce undesirable microbes in the area just inside the nose. It is believed that certain microbes such as methicillin-resistant  staphylococcus aureus  (MRSA) colonize in the nose, and the nasal insert can be effective in treating or eliminating the colony of bacteria in the nose. 
     The nasal insert can include two or more contact pads attached to one another by a spring joiner. The joiner creates tension that applies pressure to the pads. An insertion tab is removably coupled to the spring joiner. The nasal insert is inserted in the nose by grasping the insertion tab. After insertion of the nasal insert, the insertion tab can be removed from the spring joiner. Upon insertion of the nasal insert, the pads contact an area of the inner nostril. The nasal insert can be removed from the nose by grasping of the joiner. 
     The pads of the nasal insert can be formed from a blended polymer compound with a microbial agent. Processing of the blended polymer compound results in the microbial agent being trapped in the polymer. In one embodiment, the microbial agent is silver which is blended into nylon (polyamide). The blended polymer compound can be injection molded into the shape of the nasal insert. When the formed nasal insert comes in contact with other materials such as human skin and or sensitive tissue, the microbial agent entrapped in the polymer has minimal contact with the application. This provides the nasal insert with a non-leaching property of the microbial agent. 
     A blowing agent or CO 2  gas can be introduced in the process after decompression, and before molding. The gas provides at least three basic product functions. The first function is to reduce the density of the polymer. The second function is to provide space for the microbial agent to naturally react with the host environment. The microbial agent can react to its environment naturally releasing ions, yet not leave the polymer structure. The third function pertains to voids created in the molded product by the gas after cooling of the polymer. The internal voids increase internal surfaces of the polymer allowing more of the antimicrobial agent to react throughout the polymer structure than it would naturally. 
     During molding of the nasal insert, texturing and surface wave details can be formed on the outer surface of the pads to allow the product the ability to maximize contact with the host environment by increasing the surface area of the pads. Application of the surface texture increases attraction and retention of microbes to the nasal insert from the host environment by capillary action. Surface treatments can be applied to the nasal insert for increasing the surface tension thereby aiding in the adhesion of microbes during use of the nasal insert. The surface treatments can be applied by means of flame or corona treatment of the surface of the nasal insert. 
     The absorptive properties of the nasal insert allow the product the potential to draw liquid born microbes to the nasal insert, and allow for maximum contact with the host environment. The absorption can also hold to the surface various mechanically detached particulates as further reinforcement to the non-leaching properties. 
     The invention will be more fully described by reference to the following drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic diagram of a nasal insert including a pair of pads connected by a joiner. 
         FIG. 1B  is a top plan view of  FIG. 1A . 
         FIG. 1C  is a side elevational view of  FIG. 1A . 
         FIG. 2  is a schematic diagram of a tab used with the nasal insert shown in  FIG. 1A . 
         FIG. 3A  is a schematic diagram of a nasal insert including a wave pattern. 
         FIG. 3B  is a top plan view of  FIG. 3A . 
         FIG. 3C  is a side elevational view of  FIG. 3A . 
         FIG. 4  a schematic diagram of a nasal insert including four pads in which two pairs of the pads are connected by a micro-joiner and each pair of pads are connected to each other with a joiner. 
         FIG. 5A  is a plan view schematic diagram of the nasal insert shown in  FIG. 4 . 
         FIG. 5B  is a side elevational view of  FIG. 4 . 
         FIG. 6  a schematic diagram of a nasal insert including a multiple pad tube. 
         FIG. 7  is a plan view of the nasal insert shown in  FIG. 6 . 
         FIG. 8  is a flow diagram of a method of forming a nasal insert. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. 
       FIGS. 1A-1C  illustrates nasal insert  10  in accordance with the teachings of the present invention. Nasal insert  10  includes pads  11 ,  12 . Joiner  14  connects pads  11 ,  12  in a spaced apart relation to form a clip. End  15   a  of joiner  14  is coupled to pad  11  and end  15   b  of joiner  14  is coupled to pad  12 . 
     Surface  16  of pad  11  and surface  17  of pad  12  can be a textured surface. For example, surface  16  and surface  17  can include a plurality of micro-pores extending into surface  16  and surface  17  to create the textured surface. The textured surface can have a depth up to about 0.0015 inches. Length L 1  of pad  11  and pad  12  can be longer than width W 1  of pad  11  and pad  12  to form an elongated pad. Upper edge  18  of pad  11  and pad  12  and lower edge  19  of pad  11  and pad  12  can be rounded. The smooth contours and rounded edges of pad  11  and pad  12  allow for comfortable insertion, increased long wear comfort as well as increased surface area. 
     Pads  11 ,  12  can be formed of a plastic material comprising an antimicrobial agent. The plastic can be a rigid plastic. For example, pads  11 ,  12  can be formed of nylon and in particular a synthetic polyamide polymer. The antimicrobial agent is blended into a plastic pre-polymer before molding of the plastic material into pads  11 ,  12 . Suitable antimicrobial agents are metal antimicrobial agents including silver, gold, platinum, copper, zinc or palladium. The antimicrobial agents can include metal cations. The preferred metal ion is silver ion. The antimicrobial agent can be provided in an effective amount capable of interacting with a colony of microbes for suppressing colonization or killing of the colony. Example microbes include bacteria of methicillin-resistant  staphylococcus aureus  (MRSA). 
     Insertion tab  20  is removably coupled to joiner  14 , as shown in  FIG. 2 . In one embodiment, insertion tab  20  includes frangible detail  22 . Frangible detail  22  has a width W 2  which is smaller than width W 3  of insertion tab  20 , as shown in  FIG. 1 . Width W 3  is selected to provide a surface which can be grasped by a user during insertion of nasal insert  10 . Width W 2  is selected to allow insertion tab  20  to be removed from joiner  14  by twisting of insertion tab  20  to break frangible detail  22 . Frangible detail  22  can be attached within recess  24  on top  25  of joiner  14 . Frangible detail  22  is recessed into recess  24  to allow any detachment burrs from the removal of insertion tab  20  to extend within recess  24  and below top  25  of joiner  14 . Area  27  of insertion tab  20  can be used for printing indicia of product identification. Insertion tab  20  provides a point of insertion of nasal insert  10  away from the user portion of insert nasal insert  10  including pads  11 ,  12 . 
     Joiner  14  can be formed of a flexible material to bias pad  11  and pad  12  for allowing pads  11  and  12  to remain in contact with the inner nostril upon insertion of pads  11  and  12  into the nose. For example, joiner  14  can be formed of a thermoplastic material. A suitable thermoplastic material is polyurethane. Alternatively, joiner  14  can be integral with pads  11 ,  12 . Joiner  14  and pads  11 ,  12  can be formed of rigid plastic. 
     The thickness of joiner  14  can be adjusted to control the pressure exerted outwardly by pads  11 ,  12 . For example, joiner  14  can have a thickness in the range of about 0.05 inches to about 0.110 inches. Joiner  14  can have a curved shape. The curve of joiner  14  allows for variation in nose shape relieving pressure on the underside of the nose, and provides increased comfort for the wearer upon insertion of pads  11  and  12  into the nose. The narrow width of joiner  14  provides a discreet appearance of nasal insert  10  when in use. 
     A colorant can be added to the plastic material for nasal insert  10 . For example, the colorant can have a flesh tone to allow a cosmetic blend of nasal insert  10  to a user&#39;s skin and provide a less noticeable appearance. 
     In one embodiment, pad  11  and pad  12  can include a surface wave  40  on one or both of inner surface  42  and outer surface  44  as shown in  FIGS. 3A-3C . Surface wave  40  comprises a plurality of ridges  45 . Surface wave  40  can increase the surface area of pads  11  and  12  up to about 50%. 
       FIGS. 4 and 5A  and  5 B, illustrate an alternate embodiment of nasal insert  50  including a double clip. Micro-joiner  54   a  connects pad  11  to pad  51  in a spaced apart relation. End  55   a  of micro-joiner  54   a  is coupled to pad  11  and end  55   b  of micro-joiner  54   a  is coupled to pad  51 . Micro-joiner  54   b  connects pad  12  to pad  52  in a spaced apart relation. End  56   a  of micro-joiner  54   b  is coupled to pad  12  and end  56   b  of micro-joiner  54   b  is coupled to pad  52 . A pair of micro-joiners  54   a  and  54   b  can be used to connect respective pad  11  to pad  51  and pad  21  to pad  52 . 
     Micro-joiners  54   a  and  54   b  can be formed of a flexible material to bias respective pads  11  and  51  and pads  12  and  52  for allowing the pads to remain in contact with the inner nostril upon insertion of the pads into the nose. The thickness of micro-joiners  54   a ,  54   b  can be adjusted to control the pressure exerted by pads  11 ,  12 ,  51  and  52 . For example, micro-joiner  54   a ,  54   b  can have a thickness in the range of about 0.025 inches to about 0.050 inches. Micro-joiners  54   a ,  54   b  can have a curved shape. 
     In one embodiment, nasal insert  50  is formed of a thermoplastic material. A suitable thermoplastic material is polyurethane having about 80 durometer. Alternatively, pads  11 ,  12 ,  51  and  52  can be formed of a rigid plastic material, such as nylon. A flexible plastic material can be co-molded, over molded or insert molded with the plastic material. The co-molded flexible plastic material can be used to form joiner  14  and micro-joiners  54   a ,  54   b . The co-molded plastic material can be a thermoplastic material. 
       FIGS. 6 and 7  illustrate an alternate embodiment of nasal insert  60  including a multiple pad tube. A plurality of pads  61  extend from ring  63  and a plurality of pads  62  extend from ring  64 . For example, four pads  61  can extend from ring  63  and four pads  62  can extend from ring  64 . Joiner  65  connects ring  63  to ring  64  in a spaced apart relation. End  66   a  of joiner  65  is coupled to ring  63  and end  66   b  of joiner  65  is coupled to ring  64 . Pads  61  can be integral with ring  63  and pads  62  can be integral with ring  64 . Joiner  65  can be integral with ring  63  and ring  64 . In one embodiment, nasal insert  60  is formed of flexible polyurethane having about 60 durometer. 
     Nasal inserts  10 ,  50  and  60  can be formed of a plastic and/or thermoplastic material including one or more additives. The additives can include antimicrobial agents. Preferably, the antimicrobial agent is silver. Alternative antimicrobial agents include copper or any other known antimicrobial agent capable of delivery from nasal inserts  10 ,  50  and  60 . The additives can be blended into a base material for entrapping the additives throughout nasal inserts  10 ,  50  and  60 . 
     A method for manufacturing nasal insert  10 ,  50  and  60  having improved release of the entrapped microbial agents and attraction of microbes is shown in  FIG. 8 . 
     In block  102 , a base material is dehydrated. The base material is selected to be a hydroscopic material for increasing the performance of the microbial agent. The base material can be dehydrated using conventional methods including drying in an oven, forced hot air or desiccant drying. Preferably, the base material is a pre-polymer plastic, for example nylon or a thermoplastic material, such as polyurethane. The base material is preferably a material that absorbs moisture for providing a maximum breakdown of the microbial agent, and allowing for the release of the microbial agents from the base material to affect microbes. 
     In block  104 , the dehydrated base material is blended with a microbial agent. Preferably, during the blending step of block  104  the density of the base material is reduced. The density of the dehydrated base material can be reduced by blending the base material with a blowing agent or an injection of carbon dioxide gas into the base material creating a foaming effect. The foaming effect causes the base material to become porous and results in a decrease in density. The decrease in density allows for subatomic particles of the microbial agent to move more freely throughout the compound. The porosity also provides space for receiving moisture. The moisture can react with the microbial agent for accelerating the breakdown of the microbial agent thus increasing release of ions of the microbial agent from the base material. Example blowing agents include calcium carbonate and blowing agents manufactured by Reedy International as RCP40. The blowing agent can be added in an amount in the range of about 1% to about 3% by weight of the base material. 
     Example suitable microbial agents include silver, silver nano-particles, additives of silver such as are manufactured by Biomaster Antimicrobial Technology. The amount of the microbial agent used can be selected to increase the dielectric constant of the base material not to exceed the percolation threshold of the base material. An increased dielectric constant attracts negatively charged microbes providing improved ability of the base material to attract the microbes. The amount of microbial agent can be in the range of about 1% to about 25%. 
     The base material, such as a pre-polymer compound is blended with the microbial agent using heat and high compression mixing simultaneously, thereby causing the microbial agent to be evenly distributed throughout the polymer compound. Blending in this manner retains the microbial agent between the polymer strand structures. The base material can blended at a temperature in the range of about 350 degrees F. to about 475 degrees F. at a pressure in the range of about 0 to about 1500 psi. 
     In block  106 , the blended base material is molded by injection molding to form nasal insert  10 , nasal insert  50  or nasal insert  60 . During block  106 , a flexible plastic material can be co-molded with the base material for forming joiner  14  and micro-joiners  54   a ,  54   b  as described above. The cavity used in the injection mold can be selected to be larger than the desired product for providing pressure reduction and voids in the formed product to achieve a reduced density of the product. The cavity used in the injection mold can have a runout area allowing for a pressure drop, to maximize the foaming action and providing a pressure reduction and voids in the formed product to achieve a reduced density of the product. 
     In block  108 , the molded product of the nasal insert is surface treated to raise the surface tension that holds microbes to the nasal insert. For example, the molded nasal insert can be flame treated or treated with corona discharge. The surface treatment of nasal insert  10 ,  50  improves retention of microbes on nasal insert  10 ,  50  or  60 . 
     Surface treatment can also include silk screening and sputter coating of a biologically active or electrically active agent. Surface treatment can also include hydrophilization spot coating to enhance the capability to absorb and retain moisture. 
     Steps  104 - 108  are performed in a moisture free environment. In block  109 , the molded product is packaged in a UV and moisture proof package. When the package is opened for use, the nasal insert will begin to absorb moisture to about 0.2% to about 0.8% equilibrium and then continue to absorb moisture to about 1.6% saturation during use of the nasal insert. 
     It is to be understood that the above-described embodiments are illustrative of only a few of the many possible specific embodiments, which can represent applications of the principles of the invention. Numerous and varied other arrangements can be readily devised in accordance with these principles by those skilled in the art without departing from the spirit and scope of the invention.