Enzymatically crosslinked porous composite matrices for bone tissue regeneration

Abstract

Three-dimensional porous hydroxyapatite/collagen (HA/Coll) composites with a random pore structure were obtained by freeze-drying and crosslinked by an enzymatic treatment using microbial transglutaminase (mTGase). The procedure resulted in improved mechanical strength and thermal stability of the scaffolds. The scaffolds were characterized in terms of their stability (Coll release, swelling, collagenase-mediated degradation), thermal properties (thermogravimetric analysis, differential scanning calorimetry), mechanical behavior under compression and cell compatibility. Enzymatic treatment stabilized the sponges to water vapors, with measurable swelling ratio between 100% for HA/Coll/mTGase 0/100 to 5% for HA/Coll/mTGase 80/20. Weight loss in water due to Coll release was between 2 and 10% in mTGase-crosslinked samples and decreased with increasing HA content. Cultures of MG63 osteoblast-like cells and human umbilical vein endothelial cells (HUVEC) showed good adhesion and proliferation on the scaffolds, good viability (through MTT test, 100-150% of control), and good differentiation (alkaline phosphatase, up to 40 UI/L with respect to 35 UI/L for control).

Comparative analysis of gelatin scaffolds crosslinked by genipin and silane coupling agent

“…The main limitation in the use of these products is the possible presence of some unreacted crosslinker inside the scaffold with consequent formation of toxic products during in vivo biodegradation. For this reason, increasing interest has been recently gained by enzymatically [19] or naturally derived crosslinking agents, with a low toxicity [20].…”

Bioresorbable glass effect on the physico-chemical properties of bilayered scaffolds for osteochondral regeneration

“…Moreover, for I-CEL2/G 70/30 composites, swelling ratio was about 197 753% after 3 h, while at 6 and 24 h, the swelling degree did not increase significantly. At each time, swelling degree was found to decrease with increasing I-CEL2 amount, because of the lower hydrophilicity of the inorganic phase as compared to the polymeric matrix causing a decrease of the water sorption as suggested in previous works [21,22]. Fig.…”

Biodegradable polymers for dental tissue engineering and regeneration

“…Other applications of collagen relate to reconstructive skin surgery and tissue engineering scaffold for cartilage, tendon, and ligament [311]. In order to improve collagen's potential as a biomaterial it is combined with other degradable polymers [312] or is modified through cross-linking [313], association with bioactive molecules [314], and enzymatic pretreatment [315]. Moreover, composites of HA and collagen are utilized to mimic the composition of natural bone.…”