title: Poly (D,L-lactide)/nano-hydroxyapatite composite scaffolds for bone tissue engineering and biocompatibility evaluation.
abstract: Biodegradable polymer/bioceramic composite scaffolds can overcome the limitations of conventional ceramic bone substitutes such as brittleness and difficulty in shaping. However, conventional methods for fabricating polymer/bioceramic composite scaffolds often use organic solvents (e.g., the solvent casting and particulate leaching (SC/PL) method), which might be harmful to cells or tissues. In this study, Poly (D,L-lactide)/nano-hydroxyapatite (PDLLA/NHA) composites were prepared by in-situ polymerization, and highly porous scaffolds were fabricated using a novel method, supercritical CO2/salt-leaching method (SC CO2/SL). The materials and scaffolds were investigated by scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and gel permeation chromatography (GPC). GPC showed that the molecular weight of composites decreased with increase of NHA content. However, the water absorption and compressive strength increased dramatically. The SEM micrographs showed that the scaffolds with pore size about 250 microm were obtained by controlling parameters of SC CO2/SL. The biocompatibility of PDLLA/NHA porous scaffolds were evaluated in vitro and in vivo. The evaluation on the cytotoxicity were carried out by cell relative growth rate (RGR) method and cell direct contact method. The cytotoxicity of these scaffolds was in grade I according to ISO 10993-1. There was no toxicosis and death cases observed in acute systemic toxicity test. And histological observation of the tissue response (1 and 9 weeks after the implantation) showed that there are still some slight inflammation responses.
authors: Institute of Nano and Bio-Polymeric Materials, School of Material Science and Engineering, Tongji University, Shanghai, 200092, P.R. China. renjie6598@163.com
authors: Jie
authors: J
authors: Ren
authors: Peng
authors: P
authors: Zhao
authors: Tianbin
authors: T
authors: Ren
authors: Shuying
authors: S
authors: Gu
authors: Kefeng
authors: K
authors: Pan
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000009:adverse effects / Q000138:chemical synthesis*; D002470:Cell Survival; D002478:Cells, Cultured; D003188:Composite Resins / Q000009:adverse effects / Q000138:chemical synthesis / Q000737:chemistry; D017886:Durapatite / Q000009:adverse effects / Q000737:chemistry*; D005260:Female; D008297:Male; D008422:Materials Testing / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry; D011091:Polyesters / Q000009:adverse effects / Q000737:chemistry*; D051381:Rats; D011919:Rats, Inbred Strains; D017207:Rats, Sprague-Dawley; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D018786:Bone Substitutes; D003188:Composite Resins; D011091:Polyesters; C499699:hydroxyapatite-polylactide; C033616:poly(lactide); D017886:Durapatite
references: Science. 2000 Sep 1;289(5484):1498-500
references: 10991738
references: J Control Release. 2000 May 15;66(2-3):177-85
references: 10742578
references: Clin Orthop Relat Res. 1991 Jul;(268):260-9
references: 2060218
references: Science. 1993 May 14;260(5110):920-6
references: 8493529
references: Tissue Eng. 1995 Spring;1(1):15-28
references: 19877912
references: J Biomed Mater Res. 2001 Jun 5;55(3):401-8
references: 11255194
references: Biomaterials. 1996 Jul;17 (14 ):1417-22
references: 8830969
references: J Biomed Mater Res. 1997 Jul;36(1):17-28
references: 9212385
references: J Biomed Mater Res. 2001 May;55(2):141-50
references: 11255165
references: J Biomed Mater Res. 2000;53(1):1-7
references: 10634946
references: Drug Discov Today. 2001 May 1;6(9):483-487
references: 11344034
references: Biomaterials. 2004 Jun;25(13):2611-7
references: 14751747
references: J Biomed Mater Res. 1998 Dec 5;42(3):396-402
references: 9788501
references: Arch Surg. 1966 Nov;93(5):839-43
references: 5921307
references: Biomaterials. 1999 May;20(9):859-77
references: 10226712
references: J Control Release. 2000 Feb 14;64(1-3):91-102
references: 10640648
references: Biotechnology (N Y). 1994 Jul;12(7):689-93
references: 7764913
references: Biochem Biophys Res Commun. 2002 Mar 22;292(1):1-7
references: 11890663
references: Biomaterials. 1998 Jul;19(14):1275-85
references: 9720891
references: Oral Surg Oral Med Oral Pathol. 1971 Jan;31(1):134-9
references: 5275497
references: J Biomed Mater Res. 2002 Aug;61(2):301-11
references: 12007211
references: J Biomed Mater Res A. 2005 Sep 15;74(4):562-9
references: 16025492