Effect of double growth factor release on cartilage tissue engineering

The effects of double release of insulin-like growth factor I (IGF-I) and growth factor β1 (TGF-β1) from nanoparticles on the growth of bone marrow mesenchymal stem cells and their differentiation into cartilage cells were studied on PLGA scaffolds. The release was achieved by using nanoparticles of poly(lactic acid-co-glycolic acid) (PLGA) and poly(N-isopropylacrylamide) (PNIPAM) carrying IGF-I and TGF-β1, respectively. On tissue culture polystyrene (TCPS), TGF-β1 released from PNIPAM nanoparticles was found to have a significant effect on proliferation, while IGF-I encouraged differentiation, as shown by collagen type II deposition. The study was then conducted on macroporous (pore size 200-400μm) PLGA scaffolds. It was observed that the combination of IGF-I and TGF-β1 yielded better results in terms of collagen type II and aggrecan expression than GF-free and single GF-containing applications. It thus appears that gradual release of a combination of growth factors from nanoparticles could make a significant contribution to the quality of the engineered cartilage tissue. © 2011 John Wiley & Sons, Ltd

Biocompatibility of Accelerated Mineral Trioxide Aggregate on Stem Cells Derived from Human Dental Pulp

The aim of this study was to evaluate the effects of several additives on the setting time and cytotoxicity of accelerated-set mineral trioxide aggregate (MTA) on stem cells of human dental pulp. ProRoot white MTA (WMTA) (Dentsply Tulsa Dental, Johnson City, TN) was mixed with various additives including distilled water, 2.5% disodium hydrogen phosphate (Na2HPO4) (Merck, Darmstadt, Germany), K-Y Jelly (Johnson & Johnson, Markham, ON, Canada), and 5% and 10% calcium chloride (CaCl2) (Merck). The setting times were evaluated using a Vicat apparatus (Alsa Lab, Istanbul, Turkey). Human dental pulp stem cells were isolated and seeded into 48-well plates at 2 x 10(3) cells per well and incubated with MTA samples for 24 hours, 3 days, and 7 days. Cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. MTA mixed with 10% CaCl2 showed the lowest setting time (P < .05). According to the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sullophenyl)-2H-tetrazolium results on the 1st, 3rd, and 7th days, a statistically significant difference was found (P < .05) between MTA groups and the control group. MTA mixed with K-Y Jelly in all groups showed the lowest cell viability at all time points (P < .05). The cell viability of MTA mixed with distilled water, 5% CaCl2, 10% CaCl2, and Na2HPO4 increased significantly through time (P < .05). This in vitro study found MTA mixed with 5% and 10% CaCl2 and Na2HPO4 is biocompatible with dental pulp stem cells in terms of cell viability. Further in vitro and in vivo investigations are required to prove the clinical applications of MTA mixed with various additives

Advanced cell therapies with and without scaffolds

PubMedID: 22162495Tissue engineering and regenerative medicine aim to produce tissue substitutes to restore lost functions of tissues and organs. This includes cell therapies, induction of tissue/organ regeneration by biologically active molecules, or transplantation of in vitro grown tissues. This review article discusses advanced cell therapies that make use of scaffolds and scaffold-free approaches. The first part of this article covers the basic characteristics of scaffolds, including characteristics of scaffold material, fabrication and surface functionalization, and their applications in the construction of hard (bone and cartilage) and soft (nerve, skin, blood vessel, heart muscle) tissue substitutes. In addition, cell sources as well as bioreactive agents, such as growth factors, that guide cell functions are presented. The second part in turn, examines scaffold-free applications, with a focus on the recently discovered cell sheet engineering. This article serves as a good reference for all applications of advanced cell therapies and as well as advantages and limitations of scaffold-based and scaffold-free strategies. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Effect of double growth factor release on cartilage tissue engineering

PubMedID: 22081628The effects of double release of insulin-like growth factor I (IGF-I) and growth factor ß1 (TGF-ß1) from nanoparticles on the growth of bone marrow mesenchymal stem cells and their differentiation into cartilage cells were studied on PLGA scaffolds. The release was achieved by using nanoparticles of poly(lactic acid-co-glycolic acid) (PLGA) and poly(N-isopropylacrylamide) (PNIPAM) carrying IGF-I and TGF-ß1, respectively. On tissue culture polystyrene (TCPS), TGF-ß1 released from PNIPAM nanoparticles was found to have a significant effect on proliferation, while IGF-I encouraged differentiation, as shown by collagen type II deposition. The study was then conducted on macroporous (pore size 200-400µm) PLGA scaffolds. It was observed that the combination of IGF-I and TGF-ß1 yielded better results in terms of collagen type II and aggrecan expression than GF-free and single GF-containing applications. It thus appears that gradual release of a combination of growth factors from nanoparticles could make a significant contribution to the quality of the engineered cartilage tissue. © 2011 John Wiley & Sons, Ltd