Study on In-Vitro Degradation of Bioabsorbable Polymers Poly (hydroxybutyrate-co-valerate) - (PHBV) and Poly (caprolactone) - (PCL)

Suzan Aline Casarin, Sônia Maria Malmonge, Marcio Kobayashi, José Augusto Marcondes Agnelli

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DOI: 10.4236/jbnb.2011.23026                

Abstract

The increasing use of bioabsorbable polymeric materials in medicine has stimulated researchers in the materials field to search for solutions for the replacement of metallic artifacts by bioabsorbable polymers. Therefore, this study describes the in vitro degradation of PHBV, PCL and the blends of these polymers, both of which are bioabsorbable polymers. The samples were prepared by extrusion followed by injection, and subjected submitted to in vitro degradation in phosphate buffered saline solution with pH 7.3 and kept at 37° C. Through the characterization of the variation of mass, molar mass, mechanical properties and morphology, the results indicated that the samples analyzed are more stable to hydrolytic degradation when compared to other bioabsorbable polymers. The materials indicate signs of degradation after 30 days, with a small reduction in the molar mass. After 180 days, the materials indicated a significant reduction of molar mass and reduction in the mechanical properties.

Keywords

bioabsorbable polymers, (poly-(hydroxybutyrate-co-valerate)) - PHBV, (poly-caprolactone) – PCL

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Yuehuei, H. A., Shane, K. W., Friedman, R. J. Pre-clinical in vivo evaluation of orthopedic bioabsorbable devices. Biomaterials 2000; 21, p. 2635-2652.
[2]	Elke, M.; Rolf-Joachim, M. & Wolf-Dieter, D. Studies on the enzymatic hydrolysis of polyesters I. Low molecular mass model esters and aliphatic polyesters. Polymer Degradation and Stability. 2003; 80, p.485.
[3]	Huang, M. H.; Li, S.; Hutmacher, D. W.; Schantz, J. T.; Vacanti, C. A.; Braud, C. & Vert, M. Degradation and cell culture studies on block copolymers prepared by ring opening polymerization of epsilon-caprolactone in the presence of poly(ethylene glycol). Journal of biomedical materials research. 2004; 69A, p.417.
[4]	Luciano, R. M.; Zavaglia, C. A. C.; Duek, E. A. R. & Alberto–Rincon, M. C. Synthesis and characterization of poly(L-lactic acid) membranes: Studies in vivo and in vitro. Journal of materials science: Materials in medicine. 2003; 14, p.87.
[5]	Laine, P.; Kontio, R.; Lindqvist, C. & Suuronen, R. Are there any complications with bioabsorbable fixation devices? A 10 year review in orthognathic surgery. International journal of oral and maxillofacial surgery. 2004; 33, p.240.
[6]	VANIN, M. Obten??o, caracteriza??o e estudo da adsor??o de proteínas na blenda biorreabsorvível poli (?-hidroxibutirato) (PHB)/poli(l-ácido láctico) (PLLA). 212p. Tese (Doutorado em Engenharia Química)– Universidade Estadual de Campinas – Campinas – 2003.
[7]	MIDDLETON, J.C., TIPTON, A.J. Synthetic biodegradable polymers as orthopaedic devices. Biomaterials, 2000; 21, p.2335-2346.
[8]	WAKE, M.C. et al. Effects of biodegradable polymer particles on rat marrow-derrived stromal osteoblasts in vitro. Biomaterials. 1998; 19, p. 1255-1268.
[9]	ASTM D-638-02 (2002). Standard Test Method for Tensile Properties of Plastics. Annual Book of ASTM Standards.
[10]	ASTM F 1635 – 04a: “Standard test method for in vitro degradation testing of hydrolytically degradable polymer resins and fabricated forms for surgical implants” - Annual Book of ASTM Standards, Philadelphia (2004).
[11]	Vinhas, G.M.; Almeida, Y.M.B.; Lima, M.A.G.A & Santos, L.A., Estudo das propriedades e biodegradabilidade de blendas de poliéster/amido submetidas ao ataque microbiano. Química Nova, 2007, 7, 1584-1588.
[12]	Hedberg, E. L.; Shih, C. K.; Lemoine, J. J.; Timmer, M. D.; Liebschner, M. A. K.; Jansen J. A.; Mikos, A. G., In vitro degradation of porous poly(propylene fumarate)/ poly(DL-lactic-co-glycolic acid) composite scaffolds. Biomaterials 2005, 26, 3215-3225.
[13]	Barbanti, S. H.; Zavaglia, C. A. & Duek, E. A. R. Degrada??o acelerada de suportes de poli(?-caprolactona) e poli(D,L-ácido láctico-co-ácido glicólico) em meio alcalino. Polímeros: Ciência e Tecnologia, 16, 2, p. 141-148, 2006.
[14]	Duek, E. A. R., Zavaglia, C. A. C. & Belangero, W. D. In vitro study of poly(lactic acid) pin degradation. Polymer. v40, p. 6465-6473, 1999.
[15]	Canto, L. B.; Pessan, L. A.; – “Resistência à tra??o, flex?o e compress?o” In: CANEVAROLO, S. V.; – “Técnicas de caracteriza??o de polímeros” Artliber, S?o Paulo, 2 ed (2007).