NovoSorb

The NovoSorb biodegradable polyurethane has been designed to maintain physical strength and stmcture until 3 months postapplication. After this time point, progressive hydrolysis of the material resnlts in matrix degradation and absorption. 

Development history of NovoSorb biodegradable temporizing dermal matrix for major burn injury... 

The introduction of a product designed for implantation into humans requires a comprehensive development program, structured to address issues of potential toxicity, safety, and efficacy in vitro, followed by preclinical in vivo testing in appropriate animal models. Only after safety and efficacy are established, can human trials be considered. Since the employment of the NovoSorb biodegradable polyurethane platform was entirely novel in both material and concept, we followed this strategy. All trial proposals were submitted to, and approved by, the relevant Animal or Human Research Ethics Conunittee. 

The structure of NovoSorb gives it the inherent capacity to completely biodegrade by hydrolysis over variable time periods, dependent on the strategic chemical placement of the degradable chain extenders in the urethane structure. Therefore, 70 NovoSorb variants were initially synthesized, three of which were chosen as potential BTM prototypes (BTM-1, -2, and -3). At this time, we could not predict how long each of these wonld take to biodegrade in vivo. 

In vivo use of NovoSorb foam in an animal model with immediate or delayed skin graft... 

Wounds were either implanted with skin graft alone, with the 1 mm-thick NovoSorb foam with immediate skin graft applied, or foam alone with delayed skin graft applied at 11,14, or 18 days postsurgery (depending on appearance of integration). 

Immediate skin graft took completely over 1 mm-thick foam NovoSorb in three of six animals 40% surface area take in two of six and complete failure in one pig. This complete failure may have been artifact due to technical problems using a mechanical dermatome to harvest skin graft when a manual skin graft knife was used for the others, harvesting grafts of far better quality. 

The overall strategy for retiring the skin graft requires the stable and reproducible culture of recreated epithelium and neodermis in vitro by serially seeding a 1 mm-thick layer of NovoSorb with autologous fibroblasts (into the matrix) and keratinocytes (on its superficial surface). Once created, the CCS was implanted onto an integrated, delaminated BTM in the wound. Proof of this concept could herald an entirely new... 

This trial supported the early biocompatibility of the NovoSorb polyurethane, and its efficacy as an NPWT interface, in the NovoPore form. Larger numbers would need to be recruited to assess whether our findings of atraumatic dressing changes without bleeding, or the need for sharp excision of fragments, or infective complications extrapolate to wider use. 

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