Aerogels made of chitosan and chondroitin sulfate at high degree of neutralization: Biological properties toward wound healing

Abstract

In this study, highly neutralized, highly porous, and ultralight polymeric aerogels prepared from aqueous colloidal suspensions of chitosan (CS) and chondroitin sulfate (ChS) nanocomplexes, formulated as quasi-equimolar amounts of both, are described. These aerogels were designed as healing agents under the inspiration of minimizing the amount of matter applied to wounds, reducing the electrostatic potential of the material and avoiding covalent cross-linkers in order to decrease metabolic stress over wounds. Aerogels synthesized under these criteria are biocompatible and provide specific properties for the induction of wound healing. They do not affect neither the metabolic activity of cultured 3T3 fibroblasts nor the biochemical parameters of experimental animals, open wounds close significantly faster and, unlike control wounds, complete reepithelialization and scarring can be attained 14 days after surgery. Because of its hydration abilities, rapid adaptation to the wound bed and the early accelerator effect of wound closure, the CS/ChS aerogels appear to be functional inducers of the healing. Previous information show that CS/ChS aerogels improve wound bed quality, increase granulation tissue and have pain suppressive effect. CS/ChS aerogels are useful as safe, inexpensive and easy to handle materials for topical applications, such as skin chronic wounds. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2464-2471, 2018.

Ionic Nanocomplexes of Hyaluronic Acid and Polyarginine to Form Solid Materials: A Green Methodology to Obtain Sponges with Biomedical Potential

“…As shown in the videos (video S1, video S2), the microfibers were rapidly hydrated, and the material were dispersed in small pieces into the medium. Materials with similar behavior when exposed to biorelevant media have been proposed for in vitro/in vivo testing for wound healing purposes [32,34,38] and/or to be enriched with active molecules for therapeutic purposes [39,40,41]. Furthermore, other interesting characterizations regarding the interplay between cells and solid materials and obtaining the stiffness have been published.…”

“…Thus, the strategy for this type of formulations is (i) to formulate INC that provides good balance of charges and intimate mixing of oppositely charged polymeric species and (ii) to fabricate low-density sponges by freeze-drying (avoiding cryoprotectants). This has several advantages for better manipulation, such as high stability, easy storage and transportation [38], together with high therapeutic potential [7,8,32,34,38,39,41] despite their low stiffness and high lability toward hydration (see video S1, video S2). Importantly, the hydrated material stands as a gel-like mucus (if intending to dry INC by freeze-drying and further reconstitute them through hydration, cryoprotectants are required [36,48,49]), and cell cultures studies (done following the ISO 10993-5 guidelines) correspond to the cellular response to this hydrated hydrogel.…”

“…To sterilize the solid material resulting from freeze-drying the INC suspensions, the sponges were sterilized under ultraviolet 25 W light for 4 min (UV lamp, Biolight, Santiago, Chile), sealed in plastic bags in laminar flow hood, and stored in desiccators containing dried silica gel in order to avoid moisture before their use. This method was previously used by our group, and the resulting sponges were demonstrated to maintain their biological potential in in vitro [32,33] and in vivo [34] studies.…”

PHB/CHIT Scaffold as a Promising Biopolymer in the Treatment of Osteochondral Defects—An Experimental Animal Study

“…Chitosan has many attractive properties including biocompatibility, biodegradability, non-toxicity, remarkable affinity to proteins, bacterial resistance, and hemostaticity [ 18 ]. It is available in different forms (films, gels, sponges, fibers, nanoparticles, nanofibers), and thus is suitable for diverse applications in tissue engineering [ 19 ], promoting the healing process of soft and hard connective tissues [ 20 ]. Recently, in vitro studies have suggested that chitosan could promote cartilage-specific protein expression and reduce inflammatory and catabolic mediator production by chondrocytes [ 21 ].…”

Fibrous Materials Made of Poly(ε-caprolactone)/Poly(ethylene oxide)-b-Poly(ε-caprolactone) Blends Support Neural Stem Cells Differentiation

“…For example, bone tissue engineering uses 3D printed scaffolds of regular porosity and shape, which include inorganic nanoparticles as bioactive agents, in order to provide an adequate environment to bone regeneration [11,12,13,14,15]. Highly porous scaffolds with less ordering, based on the ice-segregated ionic self-assembly of complementary charged polysaccharides, have been obtained by freeze-drying for dermis regeneration [16,17].…”