Abstract:
Disclosed is an apertured hydrogel that is used in connection with an insertion device to provide comfort at the site of entry into the skin. In one embodiment, the hydrogel contains antimicrobial properties to help inhibit microbial growth at the site of insertion of the device into the skin. In the invention the apertured hydrogel is provided with a medical dressing and comprises a hydrogel having an upper surface and a lower surface, a film covering the upper surface of the hydrogel, a base sheet releasably covering to the lower surface of the hydrogel, an aperture in the film and hydrogel from the upper surface to the lower surface of the hydrogel, wherein the base sheet extends beyond the hydrogel to form a tab.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage filing under 35 U.S.C. 371 of PCT/US2011/067538, filed Dec. 28, 2011, which claims priority to U.S. Provisional Application No. 61/427,990, filed Dec. 29, 2010, the disclosures of which are incorporated by reference in their entirety herein. 
    
    
     FIELD 
     The present disclosure relates to an apertured hydrogel. In particular, the present disclosure relates to a dressing with an apertured hydrogel, with a base sheet releasably covering the hydrogel and extending beyond the hydrogel to form a tab. 
     BACKGROUND 
     Various tubes, pins, or other percutaneous devices pass through skin for a variety of functions, such as fluid delivery or medical device support. There are several types of percutaneous devices used to administer medication, such as, for example, a diabetic pumps or a Huber needle with an implanted port. Some of these devices may be connected for an extended period of time causing irritation or discomfort on the skin and increasing the risks of infection at the injection site. 
     SUMMARY 
     Disclosed is an apertured hydrogel that is used in connection with an insertion device to provide comfort at the site of entry into the skin. In one embodiment, the hydrogel contains antimicrobial properties to help inhibit microbial growth at the site of insertion of the device into the skin. The insertion device is placed adjacent the aperture in the hydrogel. Additionally, a hydrogel can have adhesive properties to help in securing the skin. 
     In one embodiment, the apertured hydrogel in provided as a medical dressing. The medical dressing comprises a hydrogel having an upper surface and a lower surface, a film covering the upper surface of the hydrogel, a base sheet releasably covering to the lower surface of the hydrogel, an aperture in the film and hydrogel from the upper surface to the lower surface. The base sheet extend beyond the hydrogel to form a tab. 
     In one embodiment, the hydrogel comprises a main body having an upper surface and a lower surface and an aperture in the main body from the upper surface to the lower surface. The aperture is provided by a retainer. 
     In one embodiment, the hydrogel is an antimicrobial. In one embodiment, the hydrogel is absorbent. In one embodiment, the hydrogel further comprises a plurality of apertures, wherein each aperture is held open by a retainer. In one embodiment, the retainer is a wall at the aperture forming a through hole in the main body at the aperture. In one embodiment, the retainer is removable from the main body. In one embodiment, removal of the retainer forms a through hole in the main body at the aperture. In one embodiment, the retainer is connected with a base sheet, wherein the base sheet is removable from the main body of the hydrogel to remove the retainer and form a through hole at the aperture in the main body. In one embodiment, the upper surface of the main body is covered with a film. In one embodiment, the main body is covered and surrounded by a dressing having an adhesive border. In one embodiment, a injection device passes through the aperture. In one embodiment, a cover dressing having an adhesive border surrounding a center free of adhesive covers the injection device and secures around the hydrogel. 
     In one embodiment, a method of creating an apertured hydrogel comprises providing a hydrogel secured to a first sheet and passing a pin through the hydrogel to form an aperture in the hydrogel, wherein the pin is secured to the first sheet and removable from the hydrogel. In one embodiment, the method further comprises removing the first sheet and pin from the hydrogel to create a through hole in the hydrogel at the aperture. In one embodiment, the method further comprises securing the hydrogel to skin and passing an injection mechanism into the through hole and skin. In one embodiment, the method further comprises providing a second sheet secured to the hydrogel. In one embodiment, the second sheet includes an adhesive surface for securing the hydrogel to a surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of an embodiment of an apertured hydrogel; 
         FIG. 2  is a top view of an embodiment of an apertured hydrogel having a gel dressing; 
         FIG. 3  is a side sectional view of an embodiment of an apertured hydrogel; 
         FIG. 4  is a side sectional view of an embodiment of an apertured hydrogel; 
         FIG. 5  is a top view of the embodiment of the apertured hydrogel of  FIG. 3  with the pin removed creating a through hole. 
         FIG. 6  is a top view of an embodiment of a cover dressing; 
         FIG. 7  is a side sectional view of an embodiment of an apertured hydrogel, injection mechanism, and cover dressing 
         FIG. 8  is a perspective view of an injection mechanism with an apertured hydrogel; 
         FIG. 9  is a top view of an embodiment of a medical dressing containing an apertured hydrogel; 
         FIG. 10  is a top view of the embodiment of  FIG. 9  with the base sheet folded under the medical dressing; 
         FIG. 11  is a side sectional view of the medical dressing of  FIG. 9 . 
     
    
    
     While the above-identified drawings and figures set forth embodiments of the invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of this invention.
     The figures may not be drawn to scale.   

     DETAILED DESCRIPTION 
       FIG. 1  is a top view of an embodiment of an apertured hydrogel  10 . The hydrogel  10  comprises a body  11  having an upper surface  12  and a lower surface  13 . In use, the lower surface  13  is typically the surface in contact with skin while the upper surface  12  is in contact with an injection mechanism  50  (see  FIGS. 7 and 8 ). The hydrogel body  11  includes at least one aperture  14 , which is a discontinuous area within the hydrogel body  11  extending from the upper surface  12  to the lower surface  13 . In this embodiment, the aperture  14  is provided by a retainer  15 . 
     Hydrogels can have adhesive properties. Therefore, the lower surface  13  in contact with the skin can aid in providing securement with the skin. Further, depending on the particular application, the upper surface  12 , such as shown in  FIG. 1 , could adhere to the injection mechanism  50 . It is understood, that a film, having apertures coinciding with the apertures  14  in the hydrogel  10 , could be provided at the upper surface  12  to prevent adhesion between the hydrogel  10  and the injection mechanism  50 . 
     As will be discussed in the various disclosed embodiments, the retainer  15 , if included, can be any number of mechanical devices or mechanisms that are capable of providing the aperture  14  in the body  11 . The retainer  15  may be provided to create a through hole  18  at the location of the aperture  14 . In the embodiment shown in  FIG. 1 , the retainer  15  is a wall that is not solid in the center and therefore creates a through hole  18  at the location of the aperture  14 . 
     The hydrogel  10  as shown in  FIG. 1  could be used by placing directly on prepared skin with an overlying injection mechanism  50 . An injection mechanism can be any type of percutaneous device. Typically, the apertured hydrogel  10  is most suitable for providing comfort and in some embodiments antimicrobial effect to injection mechanisms that remain in place for an extended period of time, such as, for example, diabetic pumps, Huber needles, orthopedic supports. The injection device  50  typically has a portion  52  that enters the skin and a portion  53  that remains outside the body. In one embodiment, a needle  52  enters the skin  60  and a hub  53  remains outside the body. The needle  52  of the injection mechanism  50  can pass through the aperture  14  and into the skin  60 . It is understood that the hydrogel  10  could be further secured to the skin  60  with tape or an overlying dressing, such as shown in  FIGS. 2-5 and 7-8 . 
     The hydrogel  10  as shown in  FIG. 1  could be used directly in combination with the injection mechanism  50  such as shown in  FIG. 8 . In such an embodiment, the hydrogel  10  could be integrally connected with hub  53  supporting the needle  52  of the injection mechanism  50 . 
       FIG. 2  is a top view of an embodiment of an apertured hydrogel  10  having a gel dressing  20 . In this embodiment the apertured hydrogel  10  includes a plurality of apertures  14  provided by retainers  15  at each aperture. In this embodiment, five apertures  14  each having a retainer  15  is shown. As depicted in  FIG. 2 , the apertures  14  can be of various sizes and it is understood that although the apertures  14  are shown circular, the apertures can be of any size or shape. Also, similar to the embodiment shown in  FIG. 1 , in this embodiment each retainer  15  is a wall that is not solid in the center and therefore creates a through hole  18  at the location of each aperture  14 . In use, a needle  52  of an injection mechanism  50  can pass through the through hole  18  and into the skin  60 . 
     In the embodiment in  FIG. 2 , the upper surface of the hydrogel  10  secures to a gel dressing  20 . The gel dressing  20  includes a film  22  with an adhesive surface that can face the skin of the user to provide securement of the hydrogel  10  to the skin. In one embodiment, the film  22  may be adhesive free on the surface in contact with the hydrogel  10 . The film  22  can prevent the upper surface of the hydrogel  10  from adhering to the injection mechanism  50 . In one embodiment, the film  22  may include an adhesive on the upper surface to aid in securing the injection mechanism  50 . In one embodiment, the film  22  is a thin, transparent, and permeable film and includes a frame  24  to provide structural support during application. To further aid in high permeability of the gel dressing  20  the adhesive may be applied in a discontinuous pattern, such as disclosed in US patent application publication 2008-0233348, herein incorporated by reference. After application to skin  60 , the frame  24  can be removed from the film  22 . In one embodiment, the film  22  includes apertures coinciding with the apertures  14  of the hydrogel  10 . 
     The hydrogel  10  as shown in  FIG. 2  could be used by placing the hydrogel containing gel dressing  20  directly on prepared skin with an overlying injection mechanism  50 . The needle  52  of the injection mechanism  50  can pass through the through hole  18  and into the skin  60 . 
       FIGS. 1 and 2  show embodiments where the retainer  15  is a fixed mechanism that generally stays in place in the body  11  of the hydrogel  10  while the injection mechanism  50  is placed in contact with the hydrogel  10 .  FIGS. 3-5  show embodiments where the retainer  15  is removable from the body  11  of the hydrogel  10  and would not be place while the injection mechanism  50  is placed in contact with the hydrogel  10 . 
       FIG. 3  is a side view of an embodiment of an apertured hydrogel  10 . Similar to  FIG. 2 , the hydrogel  10  includes a gel dressing  20 . In this embodiment the apertured hydrogel  10  includes an aperture  14  provided by a retainer  15 . 
     In the embodiment in  FIG. 3 , the upper surface  12  of the hydrogel  10  is shown secured to a gel dressing  20 . The gel dressing  20  includes a film  22  with an adhesive surface  23  that can face the skin  60  of the user to provide securement of the hydrogel  10 . In this embodiment, the gel dressing  20  includes a frame  24  to provide structural support during application of the dressing. A base sheet  26  is included on the lower surface  13  of the hydrogel  10 . In this embodiment, the retainer  15  is a pin attached to and extending from the base sheet  26 . As shown, the retainer  15  passed through the body  11  of the hydrogel  10  as well as the film  22  of the gel dressing  20 . It is understood that the retainer  15  may pass only through the body and not through the film  22  of the gel dressing  20 . The base sheet  26  includes a release material to allow it to be releasable connected to the hydrogel  10  and the adhesive surface  23  of the film  22 . 
       FIG. 3  shows a gel dressing  20  that includes film  22  extending beyond the hydrogel  10 . It is understood that in some embodiments, a film may be provided only on the upper surface  12  of the hydrogel  10  and a base sheet only on the lower surface  13 . 
       FIG. 4  is a side view of an embodiment of an apertured hydrogel  10 . In this embodiment, instead of an entire gel dressing  20 , only a film  22  at the upper surface  12  of the body  11  is included. A base sheet  26  at the lower surface  13  of the body  11  is included. The hydrogel  10  can be slightly recessed from either or both the film  22  or base sheet  26  to provide an extending tab to aid in removal of the sheet. A retainer  15  extends from both the base sheet  26  and the film  22  partially into the hydrogel body  11 . In this embodiment, at least the base sheet  26  is removable from the hydrogel body  11 . Also, the retainers  15  may be solid bodies or may include an opening to provide the through hole  18  through which the needle  52  of the injection mechanism  50  passes. Therefore, for this embodiment, the film  22  could be removable to provide the through hole  18 , or in one embodiment the film  22  may remain on the hydrogel  10  with the retainer  15  remaining and providing a through hole  18 , 
     For the embodiments shown in  FIGS. 3 and 4  depending on the application needs, the film  22  may be removable from the hydrogel  10  and/or the base sheet  26  may be removable from the hydrogel  10 . Also, either the film  22  or the base sheet  26  or both may include apertures coinciding with the aperture in the hydrogel  10 . It is understood that the retainer  15  may pass only through the body and not through the film  22  of the gel dressing  20 . The retainer  15  may be separately secured to the base sheet  26  or may be integrally formed into the base sheet  26 . 
     To use the apertured hydrogel  10  shown in  FIGS. 3 and 4 , the base sheet  26  is removed from the lower surface  13  of the body  11  thereby removing the retainer  15  from the aperture  14  in the body  11  leaving a through hole  18 . Then the exposed lower surface  13  of the body  11  can be secured to skin.  FIG. 5  is a top view of the embodiment of the apertured hydrogel of  FIG. 3  with the pin removed creating a through hole  18 . The needle  52  of the injection mechanism  50  could pass through the through hole  18  and into the skin  60 . In this embodiment, where the retainer  15  has been completely removed for the final assembly, the flow of the hydrogel could then migrate over time to be adjacent the inserted needle  52 . When an antimicrobial agent is used in the hydrogel, effective antimicrobial protection could be provided at the insertion site to the skin. 
     Shown and described in the various embodiments, the apertured hydrogel can be placed between skin and an injection mechanism  50 . The apertured hydrogel can provide a resilient body for comfort adjacent the skin. In embodiments where the hydrogel is antimicrobial, the hydrogel can also provide antimicrobial properties at the injection site. Various devices, such as, for example, tapes or dressings could be used overlying the injection mechanism to secure the injection mechanism  50  to the skin  60 . 
       FIGS. 9-11  show an alternative embodiment of an apertured hydrogel  10 . In this embodiment, the aperture  14  is a slit  19  from the perimeter  17  of the hydrogel  10  into the body  11  of the hydrogel  10 . The slit  19  includes side walls  16   a  and  16   b . In the previous embodiments, the aperture  14  is surrounded entirely by hydrogel  10 . In the embodiment shown in  FIGS. 9-11 , the aperture  14  is not entirely surrounded by hydrogel  10 . With this embodiment, where the aperture  14  is a slit  19 , the side walls  16   a  and  16   b  could be brought into contact with one another such that the aperture  14  is essentially entirely surrounded by hydrogel  10 . The hydrogel  10  can provide a stabilizing and cushioning surface, absorption, and in some embodiment antimicrobial efficacy. Therefore, it is desirable to have the aperture  14  surrounded by hydrogel  10 . 
     It is understood that the insertion device ( FIG. 11 ) would be placed within the slit  19  of the hydrogel  10 . The slit  19  may be in the shape of an essentially linear passage in to the body of the hydrogel  10  or may be in a triangular, or wedge shape. It is understood that the slit  19  should be of sufficient width to easily allow passage of an insertion needle  52  fully into the slit  19 . In one embodiment, once the insertion needle  52  is placed though the slit  19 , the side walls  16   a ,  16   b  may be manipulated to be placed nearer one another to be nearly or entirely surrounding the insertion needle  52  with hydrogel  10 . 
     If the side walls  16   a ,  16   b  come in contact with one another, the hydrogel  10  may stick to itself. The side walls  16   a  and  16   b  may be deadened, chemically or mechanically to prevent resticking. For example, sidewalls  16   a  and  16   b  could be detackified or a film may be placed over the sidewalls  16   a ,  16   b.    
     Although the apertured hydrogel  10  in  FIGS. 9-11  is shown placed in combination with a gel dressing  20  (discussed below) it is understood that similar to previously described embodiment, the apertured hydrogel  10  may be provided with or without an gel dressing  20  or directly applied to a medical device. Although not shown, a retainer  15  (similar to described previously) may be incorporated into the hydrogel  10  to maintain the aperture  14 , in this embodiment the slit  19 . 
     In this embodiment in  FIGS. 9-11  the apertured hydrogel  10  is incorporated into a gel dressing  20 . The gel dressing  20  includes a film  22  at the upper surface  12  of the hydrogel  10 . Typically the film  22  includes an adhesive  23 . In this embodiment, the adhesive  23  generally surrounds the hydrogel  10  but does not cover the hydrogel  10  to allow for better moisture permeability out of the hydrogel  10  and film  22 . It is understood, that this adhesive  23  may be the adhesive to stick the dressing to skin  60 . However, in this embodiment, and additional support film  28  with an adhesive  29  is included at a lower surface  13  of the hydrogel  10 . This support film  28  generally surrounds the hydrogel  10  but does not entirely cover the hydrogel  10  such that a portion of the hydrogel  10  would contact skin  60 . In this embodiment, the film  22  and support film  28 , wherein the support film  28  covers a portion of the lower surface  13  of the hydrogel  10 , hold in the hydrogel  10  within the gel dressing  20 . This construction, see  FIG. 11 , is desirable because during removal, the hydrogel  10  is more likely to remove with the entire gel dressing  20 . Also, as can be seen the thickness of the various layers of film and/or adhesive can be manipulated to compensate for the thickness of the hydrogel  10 . 
     In the embodiment shown in  FIGS. 9-11 , the film  22  of the gel dressing  20  includes adhesive-free extensions  25  extending outward from each of the sides of the slit  19 . These extensions  25  provide an adhesive free area that will aid in removal of the gel dressing  20  from skin  60  but also aid in allowing for manipulation of the extent to which the slit  19  is opened or closed in around the insertion device  50 . 
     A base sheet  26  is included that covers the lower surface  13  of the hydrogel  10  and in this embodiment the adhesive  29  of the support film  28 . The base sheet  26  includes a tab  27   a  that extends beyond the perimeter  17  of the hydrogel  10 , more specifically, extends beyond the film  22  and support film  28 . The base sheet  26  typically does not include adhesive and therefore the tab  27   a  aids in removing the base sheet  26  from the hydrogel  10 . 
     In the embodiment shown in  FIGS. 9-11 , the base sheet  26  covers the hydrogel  10 , includes a fold  26   a , and the tab  27   a  extends beyond the hydrogel  10  perimeter  17 . In this embodiment, additional tabs  27   b  and  27   c  are also included. Also included in the base sheet  26  is a cut  21 . Cut  21  is a through cut in the base sheet  26  that coincides with the slit  19 . Cut  21  along with the slit  19  allow for the insertion needle  52  to enter into the aperture  14 . Tabs  27   b  and  27   c , which are adhesive free, if included could be used to hold the gel dressing  20  with injection mechanism  50  in place ( FIG. 11 ) for placement over skin  60 . Once needle  52  is inserted, the base sheet  26  can be pulled by the tab  27   a  in the direction of the arrow shown in  FIG. 11 . Because of the cut  21  in the base sheet  26 , the base sheet  26  freely passes by the insertion needle  52 , and the base sheet  26  is entirely removed from the lower surface  13  of the hydrogel  10 . The hydrogel  10  and gel dressing  20  are then in contact with the skin with the needle  52  inserted. 
     In some instances the insertion device  50  may be in place over the skin and removal of the insertion device is undesirable. In that case, the apertured hydrogel  10  may be slid under the hub  53  and with needle  52  in the aperture. In the embodiments where the apertured hydrogel  10  is incorporated with a gel dressing  20  such as shown in  FIGS. 9-11 , the gel dressing  20  is slid under the hub  53  and the needle  52  is placed in the aperture  14  and cut  21  of the base sheet  26 . Once in place, the base sheet  26  can be pulled by the tab  27   a  in the direction of the arrow shown in  FIG. 11 . Because of the cut  21  in the base sheet  26 , the base sheet  26  freely passes by the insertion needle  52 , and the base sheet  26  is entirely removed from the lower surface  13  of the hydrogel  10 . The hydrogel  10  and gel dressing  20  are then in contact with the skin with the needle  52  inserted. As with other embodiments, a cover dressing  30  could be applied over the whole assembly. As with other embodiment, a removable frame  24  may be included to provide structural support to the gel dressing  20 . 
     It is understood that the various films or sheets included in a gel dressing  20  can be single layer film or multilayer composites. If a multilayer composition the multilayer portion may be over the entire gel dressing or just a portion that is a multilayer composite. For example, in the embodiment shown in  FIGS. 9-11 , film  22  may be a thin, transparent film, but at the outer border may include a foam, woven, nonwoven, or knitted material for structural support of the film  22 . 
     It is understood that the film  22  may include adhesive on both surfaces, such that the adhesive at the surface opposite adhesive  23  enables securement to the injection mechanism  50 . 
       FIG. 6  is a top view of an embodiment of a cover dressing  30  that would be suitable for securing the injection mechanism  50  to the skin  60 . The cover dressing  30  includes a film  32  having an adhesive surface  36  for contacting the skin  60 . In this embodiment, the adhesive  36  is at a perimeter of the dressing  30  while the center of the dressing  30  is essentially free of adhesive. The adhesive-free area provides the advantage that the dressing does not readily stick to the underlying injection assembly  50  and instead sticks to the surrounding skin  60 . Also, in embodiment where the hydrogel  10  is provided with a gel dressing  10 , it would be desirable for the cover dressing  30  adhesive free portion to extend over the entire area of the gel dressing  10 . In one embodiment, the film  32  is a thin, transparent, and permeable film and therefore typically includes a frame  34  to provide structural support during application. The film  32  may include single or multilayers. After application to skin  60 , the frame  34  can be removed from the film  32 . To further aid in high permeability of the cover dressing  30  the adhesive  36  may be applied in a discontinuous pattern, such as disclosed in US patent application publication 2008-0233348, the disclosure of which is herein incorporated by reference. In addition, the cover dressing  30  may included a notched portion to allow for the attached tubing of the injection mechanism to pass through and secure. Such notched portions are included on products such as 3M Tegaderm™ IV dressing available from 3M Company, St. Paul, Minn. 
       FIG. 7  is a side view of an embodiment of an apertured hydrogel  10 , injection mechanism  50 , and cover dressing  30 . As shown, a port  40  is inserted under the skin  60 . Positioned between the skin  60  and the injection mechanism  50  is the apertured hydrogel  10 . The apertured hydrogel may include the optional gel dressing  20  as described in  FIG. 2 . The apertured hydrogel in this embodiment has the retainer removed to create the through hole  18  through which the needle  52  of the injection mechanism  50  passes. It is understood that the apertured hydrogel could include a retainer as well as the through hole  18 . Overlying the injection mechanism is the cover dressing  30 . The cover dressing  30  secures to the surrounding skin  60  and provides tension to secure the injection mechanism  50  from movement while inserted into the skin. 
     A hydrogel is a cross-linked polymer gel. Hydrogels are typically very flexible. Hydrogels provide and maintain a moist environment at the contact point on skin by increasing moisture content. Generally, hydrogels can be removed without trauma to the wound. Common ingredients are for example polyvinyl alcohol, sodium polyacrylate, acrylate polymers and copolymers with hydrophilic groups. A commercially available example of a hydrogel are Flexigel Hydrogel Sheet available from Smith &amp; Nephew, Tegaderm CHG dressing available from 3M Company, St. Paul, Minn. 
     Hydrocolloids are similar to hydrogels but have the ability to absorb moisture. It is understood that for purposes of this disclosure a hydrogel or a hydrocolloid may be used. Hydrocolloids typically comprise a blend of a polymer matrix, such as a rubbery elastomer like polyisobutylene, in combination with one or more water-soluble or water-swellable hydrocolloids, such as a dry powdered mixture of pectin, gelatin and carboxymethylcellulose. Upon absorption of a liquid the hydrocolloid form a gel-like substance. 
     Hydrogels and hydrocolloids that have absorbed liquid can be somewhat flowable. In some instances, if the hydrogel  10  is desired to be used repeatedly including a retainer  15  that remains in the body  11  to hold open the through hole  18  may be desirable. In such an instance, the needle  52  can be inserted through the through hole  18  repeatedly without removal of the hydrogel  10  and optionally attached gel dressing  20 . To aid in the repeated use of the hydrogel  10 , a film could be included at the upper surface  12  of the body  10  to prevent the hydrogel  10  from sticking to the injection mechanism  50 . The film could be similar to that shown in  FIG. 2 , however in  FIG. 2  the film extends beyond and around the hydrogel  10  to provide additional securement. 
     In some instances, the hydrogel  10  may be used for one insertion of the needle  52  through a particular through hole  18 . Therefore, in such instances, use of a retainer  15  that is removable from the body  11  to create the through hole  18  through which the needle  52  may be inserted. Over time, the body  11  at the site of the aperture  14  may flow in an around the needle  52 . 
     As discussed previously, the hydrogel may contain an antimicrobial or antiseptic agent to deliver an antimicrobial agent to the skin in and around the injection site, reducing the likeliness of an infection or to treat infections of the skin or wounds. 
     There are numerous biologically active materials, which include antimicrobial agents. Examples of antimicrobial agents include Parachlorometaxylenol; triclosan; Chlorhexidine and its salts such as Chlorhexidine Gluconate, poly hexamethylene biguanide and its salts such as poly hexamethylene biguanidine chloride, iodine, idodophors; fatty acid monoesters; poly-n-vinyl pyrrolidone-iodophors; silver oxide, silver and its salts, peroxides (e.g. hydrogen peroxide), antibiotics (e.g. neomycin, bacitracin, and polymixin B). 
     The following active ingredients could also be used to suppress the regrowth or possibly treat an infection of microorganisms in the present invention: 2,2-thiobis(4-chlorophenol); 4,4-isopropylidenediphenol; 5-amino-6-chloro-o-cresol; acetaminosalol; alcloxa; aldioxa; aluminum acetate; aluminum benzoate; aluminum diacetate; aluminum formate; aluminum phenolsulfonate; ammonium iodide; ammonium phenolsulfonate; benzisothiazolinone; benzotriazole; benzoxiquine; benzylparaben; berberine chloride; boric acid; cetethyl morpholinium ethosulfate; cetethyldimonium bromide; cetrimonium tosylate; cetylpyridinium chloride; chloramine-t; chlorothymol; cloflucarban; cocotrimonium chloride; colloidal sulfur; copper usnate; dedm hydantoin; dedm hydantoin dilaurate; dequalinium acetate; dequalinium chloride; dibromopropamidine diisethionate; dichloro-m-xylenol; dichlorophene; dichlorophenyl imidazoldioxolan; diiodomethyltolylsulfone; dimethyl hydroxymethyl pyrazole; dimethylaminostyryl heptyl methyl thiazolium iodide; dodecylbenzyltrimonium chloride; domiphen bromide; ferulic acid; fluorosalan; glyoxal; hydroxymethyl dioxoazabicyclooctane; hydroxypropyl bistrimonium diiodide; ichthammol; isodecylparaben; isopropyl sorbate; lapyrium chloride; laurtrimonium trichlorophenoxide; lauryl isoquinolinium bromide; lauryl isoquinolinium saccharinate; laurylpyridinium chloride; m-cresol; mandelic acid; MDM hydantoin; MEAa-iodine; melaleuca alternifolia; methylbenzethonium chloride; mixed cresols; nonoxynol-12 iodine; nonoxynol-9 iodine; o-cresol; oxyquinoline benzoate; oxyquinoline sulfate; p-chlorophenol; p-cresol; PEG-15 dedm hydantoin; PEG-15 dedm hydantoin stearate; PEG-5 dedm hydantoin; PEG-5 dedm hydantoin oleate; phenol; phenoxyethylparaben; phenyl salicylate; polymethoxy bicyclic oxazolidine; potassium iodide; potassium lactate; potassium phenoxide; potassium troclosene; quaternium-14; quaternium-24; quaternium-8; ricinoleamidopropyltrimonium methosulfate; sodium iodide; sodium p-chloro-m-cresol; sodium phenolsulfonate; sodium phenoxide; sodium usnate; steapyrium chloride; strontium peroxide; teasorbate; tetrabutyl ammonium bromide; thiabendazole; triacetin; undecylenamide dea; undecylenamide mea; undecylenamidopropyltrimonium methosulfate; undecyleneth-6; undecylenoyl peg-5 paraben; usnic acid; zinc acetate; zinc borate; zinc phenolsulfonate; zinc sulfate; zinc undecylenate; and combinations of the foregoing. 
     The following actives could also be of use to also reduce regrowth of microorganisms on skin: 2-bromo-2-nitropropane-1,3-diol; 4-hydroxybenzoic acid; 5-bromo-5-nitro-1,3-dioxane; 7-ethylbicyclooxazolidine; ammonium benzoate; ammonium bisulfite; ammonium propionate; ammonium sulfite; behentrimonium chloride; benzalkonium bromide; benzalkonium chloride; benzalkonium saccharinate; benzethonium chloride; benzoic acid; benzyl alcohol; benzylhemiformal; bromochlorophene; butyl benzoate; butylparaben; calcium benzoate; calcium paraben; calcium propionate; calcium salicylate; calcium sorbate; calcium undecylenate; cetalkonium chloride; cetearalkonium bromide; cetrimonium bromide; cetrimonium chloride; chloroacetamide; chlorobutanol; chlorophene; chloroxylenol; chlorphenesin; climbazole; dehydroacetic acid; diazolidinyl urea; dibromohexamidine isethionate; dichlorobenzyl alcohol; dimethyl oxazolidine; DMDM hydantoin; ethyl benzoate; ethylparaben; formaldehyde; formic acid; glutaral; hexamidine; hexamidine diisethionate; hexamidine paraben; hexetidine; hydrogenated tallowtrimonium chloride; imidazolidinyl urea; iodopropynyl butylcarbamate; isobutyl benzoate; isobutylparaben; isopropyl benzoate; isopropyl cresols; isopropylparaben; lauralkonium bromide; lauralkonium chloride; laurtrimonium bromide; laurtrimonium chloride; magnesium benzoate; magnesium propionate; magnesium salicylate; MEA o-phenylphenate; MEA-benzoate; MEA-salicylate; MEA-undecylenate; methenamine; methyl benzoate; methylchloroisothiazolinone; methyldibromo glutaronitrile; methylisothiazolinone; methylparaben; myristalkonium chloride; myristalkonium saccharinate; myrtrimonium bromide; o-cymen-5-ol; o-phenylphenol; olealkonium chloride; p-chloro-m-cresol; phenoxyethanol; phenoxyisopropanol; phenyl benzoate; phenyl mercuric acetate; phenyl mercuric benzoate; phenyl mercuric borate; phenyl mercuric bromide; phenyl mercuric chloride; phenylparaben; piroctone olamine; polyaminopropyl biguanide; potassium benzoate; potassium butylparaben; potassium ethylparaben; potassium metabisulfite; potassium methylparaben; potassium o-phenylphenate; potassium paraben; potassium propionate; potassium propylparaben; potassium salicylate; potassium sorbate; potassium sulfite; propionic acid; propyl benzoate; propylparaben; quaternium-15; salicylic acid; sodium benzoate; sodium bisulfite; sodium butylparaben; sodium dehydroacetate; sodium ethylparaben; sodium formate; sodium hydroxymethylglycinate; sodium iodate; sodium metabisulfite; sodium methylparaben; sodium o-phenylphenate; sodium paraben; sodium propionate; sodium propylparaben; sodium salicylate; sodium sorbate; sodium sulfite; sodium undecylenate; sorbic acid; soytrimonium chloride; stearalkonium chloride; steartrimonium chloride; tallowalkonium chloride; tallowtrimonium chloride; thimerosal; triclocarban; triclosan; undecylenic acid; zinc pyrithione; and combinations of the foregoing. 
     US Patent application publications 2004-0247655 and 2004-0247654, the disclosure of which are herein incorporated by reference disclose adhesive compositions and antimicrobial agents used therein. For example, chlorohexidine gluconate can be included within the gel to provide continuous antimicrobial activity. A commercially available antimicrobial hydrogel is a 3M™ Tegaderm™ CHG dressing (a product of 3M Company, St. Paul, Minn.) 
     The retainer  15 , if included, can be formed of any material that will create an aperture  14  in the body  11  of the hydrogel. The retainer  15  may be a polymeric material, metal, foam, sponge, or film. The retainer  15  that remains in with the body  11  while the needle  52  is inserted, the retainer may be a resilient material, such as a foam or elastomeric polymeric material, to aid in providing comfort at the needle  52  insertion site. The retainer  15 , if a solid body at the aperture  14 , may be of a material that allows for a needle  52  to pass through. 
     The gel dressing  20  and cover dressing  30  in combination with the adhesive could have high moisture vapor permeability. One example of a suitable material is a high moisture vapor permeable film such as described in U.S. Pat. Nos. 3,645,835 and 4,595,001, the disclosures of which are herein incorporated by reference. Issued U.S. Pat. Nos. 3,645,835 and 4,595,001, the disclosures of which are hereby incorporated by reference, describe methods of making such films and methods for testing their permeability. Preferably, the film/adhesive composite should transmit moisture vapor at a rate equal to or greater than human skin. Preferably, the adhesive coated film transmits moisture vapor at a rate of at least 300 g/m 2 /24 hrs/37° C./100-10% RH, more preferably at least 700 g/m 2 /24 hrs/37° C./100-10% RH, and most preferably at least 2000 g/m 2 /24 hrs/37° C./100-10% RH using the inverted cup method as described in U.S. Pat. No. 4,595,001. 
     The film  22 ,  32 ,  28  of the dressing is preferably conformable to anatomical surfaces. As such, when applied to an anatomical surface, it conforms to the surface even when the surface is moved and can stretch and retract. One embodiment of a film is elastomeric polyurethane, polyester, or polyether block amide films. These films combine the desirable properties of resiliency, high moisture vapor permeability, and transparency. Typically, thin film dressing includes a frame  24 . The frame is made of a substrate that is less resilient than the film and may be removable from the film. 
     The adhesive used on the film typically is a pressure sensitive adhesive, and adhesives that can be applied to skin such as the acrylate copolymers described in U.S. Pat. No. RE 24,906, the disclosure of which is hereby incorporated by reference. In one embodiment, a 97:3 iso-octyl acrylate:acrylamide copolymer adhesive can be used or a 70:15:15 isooctyl acrylate: ethyleneoxide acrylate:acrylic acid terpolymer, as described in U.S. Pat. No. 4,737,410 (Example 31), the disclosure of which is hereby incorporated by reference. Other useful adhesives are described in U.S. Pat. Nos. 3,389,827, 4,112,213, 4,310,509, and 4,323,557, the disclosures of which are hereby incorporated by reference. Inclusion of medicaments or antimicrobial agents in the adhesive is also contemplated, as described in U.S. Pat. Nos. 4,310,509 and 4,323,557 both of which are hereby incorporated by reference. 
     Silicone adhesive can also be used. Generally, silicone adhesives can provide suitable adhesion to skin while gently removing from skin. Suitable silicone adhesives are disclosed in PCT Publications WO2010/056541 and WO2010/056543, the disclosure of which are herein incorporate by reference. 
     The pressure sensitive adhesives described above typically transmit moisture vapor at a rate greater to or equal to that of human skin. While such a characteristic can be achieved through the selection of an appropriate adhesive, it is also contemplated in the present invention that other methods of achieving a high relative rate of moisture vapor transmission may be used, such as pattern coating the adhesive on the backing, as described in U.S. Pat. No. 4,595,001 which is hereby incorporated by reference. Also, it is understood that the entire surface of the film may include adhesive or the adhesive may be on select portions of the film. Therefore, the adhesive could be applied in selection regions of the film in a continuous or discontinuous manner. 
     Release liners (i.e., the base sheet) maybe used with the gel dressing  20  and cover dressing  30  to removably cover the adhesive containing surface. Release liners can be made of kraft papers, polyethylene, polypropylene, polyester or composites of any of these materials. The liners are preferably coated with release agents such as fluorochemicals or silicones. For example, U.S. Pat. No. 4,472,480, the disclosure of which is hereby incorporated by reference, describes low surface energy perfluorochemical liners. Suitable liners are papers, polyolefin films, or polyester films coated with silicone release materials. Examples of commercially available silicone coated release papers are POLYSLIK™ silicone release papers available from James River Co., H. P. Smith Division (Bedford Park, Ill.) and silicone release papers supplied by Daubert Chemical Co. (Dixon, Ill.). One example of a liner is 1-603KG-157 paper liner available from Daubert, which is a super calendared Kraft paper with a water-based silicone release surface. 
     Although specific embodiments of this invention have been shown and described herein, it is understood that these embodiments are merely illustrative of the many possible specific arrangements that can be devised in application of the principles of the invention. Numerous and varied other arrangements can be devised in accordance with these principles by those of ordinary skill in the art without departing from the spirit and scope of the invention. Thus, the scope of the present invention should not be limited to the structures described in this application, but only by the structures described by the language of the claims and the equivalents of those structures.