title: A poly(lactide) stereocomplex structure with modified magnesium oxide and its effects in enhancing the mechanical properties and suppressing inflammation.
abstract: Biodegradable polymers such as poly(L-lactide) (PLLA) have been widely utilized as materials for biomedical applications. However, the relatively poor mechanical properties of PLLA and its acid-induced cell inflammation brought about by the acidic byproducts during biodegradation pose severe problems. In this study, these drawbacks of PLLA are addressed using a stereocomplex structure, where oligo-D-lactide-grafted magnesium hydroxide (MgO-ODLA) is synthesized by grafting d-lactide onto the surface of magnesium hydroxide, which is then blended with a PLLA film. The structure, morphology, pH change, thermal and mechanical properties, in-vitro cytotoxicity, and inflammation effect of the MgO-ODLAs and their PLLA composites are evaluated through various analyses. The PLLA/MgO70-ODLA30 (0-20 wt%) composite with a stereocomplex structure shows a 20% increase in its tensile strength and an improvement in the modulus compared to its oligo-L-lactide (PLLA/MgO70-OLLA30) counterpart. The interfacial interaction parameter of PLLA/MgO70-ODLA30 (5.459) has superior properties to those of PLLA/MgO70-OLLA30 (4.013) and PLLA/Mg(OH)2 (1.774). The cell cytotoxicity and acid-induced inflammatory response are suppressed by the neutralizing effect of the MgO-ODLAs. In addition, the inflammatory problem caused by the rapid acidification of the stereocomplex structure is also addressed. As a result, the stereocomplex structure of the MgO-ODLA/PLLA composite can be used to overcome the problems associated with the biomedical applications of PLLA films.
authors.affiliation: Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, 136-791, Republic of Korea; Department of Chemical and Biological Engineering, Korea University, Seoul, 136-701, Republic of Korea.
authors.forename: Chang Hun
authors.initials: CH
authors.lastname: Kum
authors.forename: Youngjin
authors.initials: Y
authors.lastname: Cho
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Seo
authors.forename: Yoon Ki
authors.initials: YK
authors.lastname: Joung
authors.forename: Dong June
authors.initials: DJ
authors.lastname: Ahn
authors.forename: Dong Keun
authors.initials: DK
authors.lastname: Han
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D002470:Cell Survival; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004146:Dioxanes / Q000737:chemistry; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007249:Inflammation / Q000473:pathology*; D015850:Interleukin-6 / Q000378:metabolism; D019344:Lactic Acid / Q000737:chemistry; D008276:Magnesium Hydroxide / Q000737:chemistry; D008277:Magnesium Oxide / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D053761:Nanocomposites; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013237:Stereoisomerism; D013314:Stress, Mechanical; D013718:Tensile Strength; D013818:Thermogravimetry; D023822:Tissue Engineering / Q000379:methods; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D020298:U937 Cells
chemical_list: D001672:Biocompatible Materials; D004146:Dioxanes; C508600:IL6 protein, human; D015850:Interleukin-6; D011091:Polyesters; D011108:Polymers; D014409:Tumor Necrosis Factor-alpha; D019344:Lactic Acid; D008277:Magnesium Oxide; C033616:poly(lactide); C091880:dilactide; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D008276:Magnesium Hydroxide
keywords: bioinspired materials; biomaterials; inflammation; pH neutralization; polylactide; polymers; stereocomplex; structure-property relationships