,Se Heng Oh,Dn Bi An,

aHannam University,Daejeon 305-811,Republic of Korea

bDankook University,Cheonan 330-714,Republic of Korea

Dual growth factor-immobilized microspheres for tissue reinnervation

Tae Ho Kima,Se Heang Ohb,Dan Bi Ana,Jin Ho Leea,*

aHannam University,Daejeon 305-811,Republic of Korea

bDankook University,Cheonan 330-714,Republic of Korea

A R T I C L E I N F O

Article history:

Available online 25 November 2015

Microsphere

Basic fbroblast growth factor(BFGF)

Nerve growth factor(NGF)

Neurogenic differentiation

Nerve regeneration

It has been reported that various progenitor cells or stem cells and continuously released bioactive molecules can enhance the regeneration of muscles and thus help to treat chronic degenerative diseases,such as urinary/fecal incontinence and erectile dysfunction.However,the regeneration of muscles alone cannot be a fundamental cure of chronic degenerative diseases,because regenerated muscles with insuffcient nerve connections subsequently lead to muscle atrophy[1].To prevent the atrophy and maintain the function of the regenerated muscles,the reinnervation of muscles by appropriate nerves is an essential parameter.Therefore,the use of various stem cells combined with bioactive molecules which can induce neurogenic differentiation and thus enhance nerve regeneration, may be additional biological cues for the restoration of healthy muscles.On the basis of the literatures,it was expected that if a biological cues[i.e.,stem cells or growth factors(GFs)for nerve restoration]-loaded matrix system could be properly prepared,it may be very helpful to prevent the atrophy of regenerated muscles by suffcient reinnervation,and thus can be a fundamental therapy for chronic degenerative diseases. In this study,growth factors[basic fbroblast growth factor(bFGF) and/or nerve growth factor(NGF)]-immobilized polycaprolactone (PCL)/Pluronic F127 microspheres were prepared using an isolated particulate-melting method[2]and the sequential binding of heparin and growth factors(GFs)onto the microspheres[3]. The GFs immobilized on the microspheres were released in a sustained manner over 28 days,regardless of GF type(Fig.1). From the in vitro culture of muscle-derived stem cells,it was observed that the NGF-immobilized microspheres induced more neurogenic differentiation than the bFGF-immobilized microspheres,as evidenced by a quantitative real time polymerase chain reaction using specifc neurogenic markers (Nestin,GFAP,β-tubulin,and MAP2)andWestern blot(markers, Nestin and β-tubulin)analyses.The dual bFGF/NGF-immobilized microspheres showed better neurogenic differentiation than the microspheres immobilized with single bFGF or NGF.Fromthe preliminary animal study,the dual bFGF/NGF-immobilized microsphere group also showed effective nerve regeneration, as evaluated by immunocytochemistry using a marker, β-tubulin.The dual bFGF/NGF-immobilized PCL/Pluronic F127 microspheres may be a promising candidate for nerve regeneration in certain target tissues(i.e.,muscles)leading to suffcient reinnervation.

Fig.1–Cumulative released amount of growth factors on the PCL/F127 microspheres with and without heparin(n=3, *p＜0.05).

Acknowledgements

This work was supported by grants from the Korea Ministry of Health and Welfare(Grant No.HI14C0522).

R E F E R E N C E S

[1]Kim JR,Oh SH,Kwon GB,et al.Acceleration of peripheral nerve regeneration through asymmetrically porous nerve guide conduit applied with biological/physical stimulation. Tissue Eng 2013;19A:2674–2685.

[2]Lim SM,Lee HJ,Oh SH,et al.Novel fabrication of PCL porous beads for use as an injectable cell carrier system.J Biomed Mater Res 2009;90B:521–530.

[3]Oh SH,Kim IG,Lee JY,et al.Bioactive porous beads as an injectable urethral bulking agent:in vitro evaluation on smooth muscle cell differentiation.Tissue Eng 2011;17A:655–664.

*E-mail address:jhlee@hnu.kr.

Peer review under responsibility of Shenyang Pharmaceutical University.

http://dx.doi.org/10.1016/j.ajps.2015.11.077

1818-0876/?2016 Production and hosting by Elsevier B.V.on behalf of Shenyang Pharmaceutical University.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).