Physical and mechanical evaluation of novel flexible Chitosan/bioactive glass composite foams crosslinked with adipic acid for tissue engineering scaffolds

摘要

The development of Tissue Engineering for biological substitutes has the purpose not only to fill space but also to allow regeneration and function improvement of the damaged tissues. One issue in this area is the design and fabrication of suitable scaffolds, usually porous, with adequate pore size and interconnectivity, which act as templates for cell adhesion, growth, and proliferation. Different approaches to the development of bioactive composites for soft and hard tissue engineering are being investigated. With this very purpose, a strong alternative is the design of 3D matrices produced by foaming which support cell culture, thanks to their high porosity and large surface area. Moreover, a critical component to be considered on the design and utilization of these biomaterials is a suitable mechanical integrity for medical devices. To reach such a result, the materials used during the composite formation process should have characteristics that qualify them as biomaterials and properties that make them likely to be processed. One of the polymers which best meets the requirements is Chitosan (CHI) due to its biocompatibility, biodegradability, antimicrobial activity and high adhesiveness. Combined with this polymer, the bioactive glasses (BG) are a subset of inorganic bioactive materials, which are capable of reacting with physiological fluids especially in regeneration of bones and teeth, but as some studies demonstrate, they are able to stimulate the healing also in soft tissue. Besides, an antibacterial behavior has also been reported for BG. In this study, scaffolds of CHI and BG in the ratio of 1:0 and 1:1 in an adipic acid solution 1% were prepared by a foaming method. Physical characterizations were performed by FTIR, RAMAN spectroscopy and SEM, in order to evaluate the structural characteristics and the porosity of the samples. The mechanical assays performed were state tensile and compression testing. Cytotoxicity tests were conducted by using the MTT assay. The scaffolds obtained presented a homogeneous pore structure with interconnectivity. The mechanical assays demonstrated a viscoelastic behavior for both materials. The produced foams showed biocompatibility and bioactivity, and they may be alternative biomaterials for healing stimulation.