Fang Wu

Name:

Organization: Sichuan University

Department: National Engineering Research Center for Biomaterials

Title:

Chemicals
References

Zn and Sr incorporated 64S bioglasses: Material characterization, in-vitro bioactivity and mesenchymal stem cell responses

Co-reporter:Xiaoli Wu, Guolong Meng, Shanling Wang, Fang Wu, Wanxia Huang, Zhongwei Gu

Materials Science and Engineering: C 2015 Volume 52() pp:242-250

Publication Date(Web):1 July 2015

DOI:10.1016/j.msec.2015.03.057

•We synthesized the Zn (2%) and Sr (5%) doped 64S bioglasses, alone and co-doped.•Most of Sr appeared to form a secondary crystal phase.•Sr demonstrated a stimulating effect only on MSC differentiation.•We suggest likely different stimulating mechanisms of Sr and Zn toward MSC responses.Essential element like Zn or Sr is known to play an important role in bone remodeling process. In this study, we have used the sol–gel process to synthesize the Zn (2%) and Sr (5%) doped 64S bioglasses (BGs, 64SiO2–5P2O5–31CaO, mol.%), alone and co-doped. The synthesized glasses were characterized by XRD, FTIR and STEM. For biological evaluation, the effects of Zn and Sr incorporation on the in vitro bioactivity of the synthesized BGs were studied using the simulated body fluid (SBF) soaking. The proliferation and differentiation (ALP, OCN) of rat mesenchymal stem cells (MSCs) on these BGs were studied using CCK-8 and ELISA analyses. The results indicated that Zn had been uniformly incorporated into the bioglass, and demonstrated a stimulating effect on apatite-like layer formation, MSC proliferation and differentiation. On the other hand, most of Sr appeared to form a secondary crystal phase with extremely high solubility in SBF, showing an enhancing effect only in MSC differentiation but not in proliferation, as well as an inhibitory effect on apatite-like layer formation. The different dissolution behaviors of Sr and Zn ions seemed to have a strong correlation with the different apatite-like layer formation capabilities and the cellular responses of Zn and Sr containing BGs.

Antibiotic-Loaded Chitosan Hydrogel with Superior Dual Functions: Antibacterial Efficacy and Osteoblastic Cell Responses

Co-reporter:Fang Wu, Guolong Meng, Jing He, Yao Wu, Fang Wu, and Zhongwei Gu

ACS Applied Materials & Interfaces 2014 Volume 6(Issue 13) pp:10005

Publication Date(Web):June 18, 2014

DOI:10.1021/am502537k

It is critical for the clinical success to take the biological function into consideration when integrating the antibacterial function into the implanted biomaterials. To this aim, we prepared gentamycin sulfate (GS)-loaded carboxymethyl-chitosan (CM-chitosan) hydrogel cross-linked by genipin. The prepared hydrogels not only achieved superb inhibition on bacteria growth and biofilm formation of Staphylococcus aureus but also significantly enhanced the adhesion, proliferation, and differentiation of MC3T3-E1 cells. The observed dual functions were likely based on the intrinsic property of the positive charged chitosan-based hydrogel, which could be modified to selectively disrupt the bacteria wall/membrane and promote cell adhesion and proliferation, as suggested by the membrane permeability study. The genipin concentration played an important role in controlling the degradation time of the chitosan hydrogel and the MC3T3-E1 cell responses. The loading of GS not only significantly increased the antibacterial efficiency but also was beneficial for the osteoblastic cell responses. Overall, the biocompatibility of the prepared chitosan-GS hydrogel could be tuned with both the genipin and GS concentrations, which control the available positive charged sites of chitosan. The results demonstrated that chitosan-GS hydrogel is an effective and simple approach to achieving combined antibacterial efficacy and excellent osteoblastic cell responses, which has great potential in orthopedic applications.Keywords: biofilm; carboxymethyl chitosan; gentamycin sulfate; hydrogel; membrane permeability

Collagen-infiltrated porous hydroxyapatite coating and its osteogenic properties: In vitro and in vivo study

Co-reporter:Jing He;Tao Huang;Lu Gan;Zongke Zhou;Bo Jiang;Yao Wu;Zhongwei Gu

Journal of Biomedical Materials Research Part A 2012 Volume 100A( Issue 7) pp:1706-1715

Publication Date(Web):

DOI:10.1002/jbm.a.34121

Abstract

Bone–implant interface is critical for the early fixation of orthopedic implants. In this study, porous hydroxyapatite (HA) coatings were prepared through a liquid precursor plasma spraying process and were infiltrated with the collagen, alone and with the additional incorporation of recombinant human bone morphogenetic protein-2 (rhBMP-2) and RGD peptide (RGD). The results showed significantly improved mesenchymal stem cell (MSC) adhesion, proliferation, and differentiation on collagen-modified HA coatings, partially benefited from the formation of a fibrous network due to the self-reconstitution of collagen on the HA surface. Further enhancements on MSC proliferation and differentiation were generally observed through the additional incorporation of bone morphogenetic protein (BMP) and RGD. The osteoinductive and osteoconductive properties of the collagen/BMP-modified HA coatings were studied in vivo. Clear ectopic bone formation and significantly accelerated bone growth rate (29% increase, p < 0.05) have been observed after 1-month implantation of HA–collagen/rhBMP-2-coated Ti alloy samples into the rabbit muscle and dog femora, respectively. Overall, our results suggest that collagen-modified HA coating surface is a far superior substrate for cell attachment, proliferation, and differentiation, and collagen can be used an efficient carrier for BMP in vivo. Therefore, modification of HA coating with collagen is a simple but effective biomimetic approach to enhancing the osteointegration and early fixation of bone–implant interface. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.

Antibacterial hydroxyapatite/chitosan complex coatings with superior osteoblastic cell response

Co-reporter:Lei Song, Lu Gan, Yan-Feng Xiao, Yao Wu, Fang Wu, Zhong-Wei Gu

Materials Letters 2011 Volume 65(Issue 6) pp:974-977

Publication Date(Web):31 March 2011

DOI:10.1016/j.matlet.2010.12.051

Chitosan was widely used as an antibacterial component. While most antibacterial materials also possess cytotoxicities, we hypothesize that selectively destruction of bacterial cells can be achieved by controlling the material parameters of chitosan, due to its intrinsic antibacterial mechanism. In this study, porous hydroxyapatite coatings prepared by the liquid precursor plasma spraying process were used for loading the chitosan with different concentrations: 10, 20, 50, and 100 g/L, respectively. The antibacterial properties and osteoblastic cell response of the hydroxyapatite/chitosan complex coatings were studied as a function of chitosan concentration. The results indicated that the antimicrobial activity was directly proportional to the chitosan concentration, while loading of chitosan with lower concentrations (10 and 20 g/L) was even beneficial to the proliferation of osteoblastic cells. Overall, our study demonstrated that combined antibacterial activity and superior osteoblast cell response can be achieved by using hydroxyapatite/chitosan complex coatings, which have great potential in bone replacement and regeneration applications.