Bilayer Cryogel Wound Dressing and Skin Regeneration Grafts for the Treatment of Acute Skin Wounds

Abstract

In this study, the potential of cryogel bilayer wound dressing and skin regenerating graft for the treatment of surgically created full thickness wounds was evaluated. The top layer was composed of polyvinylpyrrolidone-iodine (PVP-I) cryogel and served as the antiseptic layer, while the bottom regenerative layer was made using gelatin cryogel. Both components of the bilayer showed typical features of a cryogel interconnected macropore network, rapid swelling, high water uptake capacity of about 90%. Both PVP and gelatin cryogel showed high tensile strength of 45 and 10 kPa, respectively. Gelatin cryogel sheets were essentially elastic and could be stretched without any visible deformation. The antiseptic PVP-I layer cryogel sheet showed sustained iodine release and suppressed microbial growth when tested with skin pathogens (zone of inhibition ∼2 cm for sheet of 0.9 cm diameter). The gelatin cryogel sheet degraded in vitro in weeks. The gelatin cryogel sheet supported cell infiltration, attachment, and proliferation of fibroblasts and keratinocytes. Microparticles loaded with bioactive molecules (mannose-6-phosphate and human fibrinogen) were also incorporated in the gelatin cryogel sheets for their role in enhancing skin regeneration and scar free wound healing. In vivo evaluation of healing capacity of the bilayer cryogel was checked in rabbits by creating full thickness wound defect (diameter 2 cm). Macroscopic and microscopic observation at regular time intervals for 4 weeks demonstrated better and faster skin regeneration in the wound treated with cryogel bilayer as compared to untreated defect and the repair was comparable to commercial skin regeneration scaffold Neuskin-F. Complete skin regeneration was observed after 4 weeks of implantation with no sign of inflammatory response. Defects implanted with cryogel having mannose-6-phosphate showed no scar formation, while the wound treated with bilayer incorporated with human fibrinogen microparticles showed early signs of skin regeneration; epidermis formation occurred at 2 weeks after implantation.

Biomimetic Photocurable Three-Dimensional Printed Nerve Guidance Channels with Aligned Cryomatrix Lumen for Peripheral Nerve Regeneration

“…[20][21][22][23] Over the last decade, cryogels, a form of hydrogels with interconnected pores fabricated using cryogelation technology have shown tremendous applications in the tissue engineering and regenerative medicine. [24][25][26][27][28] We hypothesized that a 3D printed nerve guidance channel filled with aligned cryomatrix supplemented with NGF (aCG+NGF) will lead to efficient regeneration of the critical size nerve injuries. To augment this, in this work we fabricated and evaluated an aligned cryomatrix filled 3D printed guidance channels by a combinatorial approach, making use of stereolithography and cryogelation technology.…”

Influence of the weight ratio of polydimethylsiloxane modified gelatin to silicone rubber on the potential performance of asymmetric bilayer membranes as wound dressings

“…As also shown in Table S2, the PGE/SR1 had a higher porosity of 64%, which was in the usual range of 60%–90% for a bilayer wound dressing . Additionally, the adequate pores in the lower layer, basically derived from GE, not only can allow medium and other nutrients to reach them freely but also can facilitate cell adhesion in the wound dressing …”

“…4 Additionally, the adequate pores in the lower layer, basically derived from GE, not only can allow medium and other nutrients to reach them freely but also can facilitate cell adhesion in the wound dressing. 31 The surface morphology of the prepared membranes was further observed by SEM. Figure 2 displays the upper and lower surface morphology of PGE/SR1, PGE/SR2 and PGE/SR3 bilayer membranes, and the corresponding average pore size and distribution are shown in Fig.…”

Biomedical Applications of Polymeric Cryogels

“…Cell infiltration and attachment Proliferation of fibroblasts and keratinocytes In vivo: Regeneration ability was proven in implanted rabbits Resembling to commercial skin regeneration product Neuskin-F [93] 3.4.4. Other Tissue Engineering Applications Cardiovascular grafts usage has not been appropriate because of donor availability.…”