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Abstract

Poly(lactic acid) (PLA) and other polyester-based polymers are broadly used in biomedical applications due to their favourable mechanical strength and biodegradable properties. However, the acidic properties of their degradation products may lead to clinical complications, such as inflamation, long-term osteoporosis and other unpredictable issues. In this study, we demonstrate the superior properties of the poly(propylene carbonate) (PPC)-starch composite as an alternative to polyester-based biomaterials. The degradation products of PPC-starch are mainly carbon dioxide and water. Hence, the pH in the surrounding tissues of an implant fabricted from this composite does not decrease. Moreover, the mechanical strength of PPC-starch composites is tuneable within the range of 0.2�±0.03 MPa to 33.9�±1.51 MPa, by varying the starch content from 0-50 w%. PPC-starch composites are cytocompatible as osteoblast cells adhere and proliferate on their surface within seven days. The long-term biocompatibility of PPC-starch is assessed via subcutaneous implantation in mice. The results of histological analysis demonstrate no symptom of inflammation for PPC-starch composite after eight weeks implantation, while the biodegradation of PLA lead to massive immune cell infusion and inflammation. These results underline that PPC-starch is suitable for biomedical applications and can be used for the musculoskeletal tissue regeneration. Figure 1: The explanation site of PPC-ST50 (a) and PLA (b) 8 weeks post-surgery, and haematoxylin and eosin staining of paraffin sections of the implantation site at 8 weeks around PPC-ST50 composite (c) and PLA (d). After 8 weeks a prominent foreign body reaction is observed around PLA implantation zone. However, the inflammatory response to the PPC-ST50 composite is resolved dramatically.

Biography

Email: fariba.dehghani@sydney.edu.au