(WHS-P90) A NOVEL BIO-INSPIRED SKIN GRAFT ADHESIVE
Friday, May 17, 2024
7:30 AM – 5:00 PM East Coast USA Time
Full-thickness burn injuries are commonly treated with autologous split-thickness skin grafts (STSGs). Different strategies may be used to hold STSGs in place including staples and vacuum drapes. To enhance fixation across the entire graft, fibrin glue may be sprayed onto the wound bed prior to graft placement. Though fibrin glue significantly improves graft adhesion to the wound bed, it can be expensive and has been reported to increase inflammation and impair epithelial cell migration. The goal of this study was develop a new strategy for promoting adhesion of STSGs a to the wound bed. To achieve this, polydopamine nanoparticles (PDA-NPs) were produced by dissolving 0.5mg/mL dopamine hydrochloride-anhydrous (DHA) in water. The DHA solution was then titrated with 1N NaOH at a ratio of 3.33uL NaOH/ml DHA solution. The resulting solution was aliquoted into micro-centrifuge tubes and centrifuged at 13,750rpm. The pellets were lyophilized for 18 hours then diluted in unsupplemented DMEM with bovine serum albumin (BSA) to the desired PDA-NP concentration. To examine adhesion strength as a function of PDA-NP concentration and type/duration of near infrared laser excitation, human surgical discard tissue was collected from panniculectomies and STSGs harvested (0.008”). To create a “wound bed”, an additional piece of tissue was harvested below the STSG at a depth of 0.032”. Dog-bone shaped samples were punched from STSG and the “wound bed”, and PDA-NP-BSA solution applied to the tab portion of the dog bone punches at a volume of 30µL/cm2 and a PDA-NP concentration between 0-1000µg/cm2. PDA-NPs were excited by exposure to near infrared (NIR) laser in different durations and exposure patterns. Samples were then secured into a uniaxial tensile tester and strained at 1mm/sec. Initial testing with a PDA-NP at a concentration of 1000µg/cm2 with a fine pattern NIR laser exposure (3x3 grid with ~1mm diameter spot size) significantly improved adhesion compared to wide NIR laser (1x2 grid with l~3mm diameter spot size) and 0 µg/cm2 controls. Subsequent testing showed that using 1000 µg/cm2 PDA-NPs with 15 min incubation on the wound bed prior to NIR excitation resulted in an average adhesive force of 0.13N while using 500 µg/cm2 with incubation yielded an average of 0.11N Biocompatibility assessed via MTT assay, showed no difference in no NIR exposure, no PDA-NPs controls and any PDA-NP concentration (0-1000 µg/cm2 ) or NIR exposure (fine or wide). Studies are ongoing examining the adhesion of human STSGs to full-thickness wounds in athymic mice compared to fibrin glue along with an examination of STSG integration and inflammation in this model. The above results suggest that PDA-NP-BSA solutions can be used as a medical adhesive to secure STSGs to the wound bed and may provide improvements in associated inflammation compared to fibrin-based glues.