Abstracts / Journal of Controlled Release 259 (2017) e5–e195
removed in the slightly acidic condition. PEGylation also effectively decreased the cytotoxicity of the complexes. This pH-sensitive PEGylation is a practical and promising strategy for polycationic gene delivery system in cancer therapy.
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time for the grafts was about 7 days. The transparency of the cornea was soon restored (Fig. 1b). With the degradation of collagen in vivo, microRNA could be released and worked in corneal stroma cells. Optical coherence tomography images indicated the scar tissue of cornea that transplanted with collage membrane which loaded microRNA-133b was not obvious (Fig. 1c), while an obvious scar tissue was observed in the group that transplanted with nonmodified collagen. These results suggested the material had a good effect of corneal stroma repair, espically in the inhibition of the scar formation.
Fig. 1. The facile pH-sensitive shielding strategy for polycationic gene delivery system.
Keywords: pH-sensitive, PEGylation, shielding, gene delivery, cancer therapy Acknowledgements The authors are thankful for the National Natural Science Foundation of China (21474104, 51222307, 51321062, 51233004, 51403205, 51390484 and 51303173) for financial support to this work.
Fig. 1. Collagen membrane with excellent suturability (a), biocompatibility (b) and ability of inhibition of scar tissue formation (c).
References
Keywords: cornea repair, collagen, wound healing, microRNA therapy, biomaterials
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doi:10.1016/j.jconrel.2017.03.317
Acknowledgements This work was financially supported by National Natural Science Foundation of China (51273072, 51232002), Guangzhou Important Scientific and Technological Special Project (201508020123), National Basic Research Program of China (2012CB619100), Guangdong Scientific and Technological Project (2014B090907004). References
Modified collagen-based materials with MicroRNA for enhanced corneal tissue repair by the regulation of corneal wound healing Xuan Zhao, Wenjing Song⁎, Li Ren⁎ National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China ⁎Corresponding authors. E-mail addresses:
[email protected] (X. Zhao),
[email protected] (W. Song),
[email protected] (L. Ren) Corneal disease is the main cause of blindness and keratoplasty is the only widely accepted treatment. Due to the shortage of donor tissue, researchers had focused on the research and development of materials to replace donor corneas or repair cornea tissue [1]. Collagen is the main component of corneal stroma, so it becomes a promising material for corneal repair [2]. In our previous work, a collagen membrane with enhanced mechanical properties including suturability was developed (Fig. 1a). This kind of membrane also exhibited outstanding biocompatibility [3]. However, keratoplasty or transplantation of materials can lead to formation of scar tissue in corneal stroma and it may affect the recovery of vision. Hence, a modified collagen membrane with microRNA-133b on the surface was fabricated to relieve or inhibit the scar tissue formation. MicroRNA-133b was found to have the function of downregulating the protein expression which related to the scar formation. After loading by Au nanoparticles, microRNA-133b was adsorbed on the surface of collagen based membrane. Physical and chemical properties such as transmittance, water content, tensile strength and suturability were characterized. The re-epithelialization
[1] H.Y. Wang, R.H. Wei, S.Z. Zhao, Evaluation of corneal cell growth on tissue engineering materials as artificial cornea scaffolds, Int. J. Ophthalmol. 6 (2013) 873-878. [2] M. Griffith, R. Osborne, R. Munger, X. Xiong, C.J. Doillon, N.L. Laycock, M. Hakim, Y. Song, M.A. Watsky, Functional human corneal equivalents constructed from cell lines, Science 286 (1999) 2169-2172. [3] X. Zhao, Y. Liu, W.C. Li, K. Long, L. Wang, S. Liu, Y.J. Wang, L. Ren, Collagen based film with well epithelial and stromal regeneration as corneal repair materials: improving mechanical property by crosslinking with citric acid, Mater. Sci. Eng. C. Mater. Biol. Appl. 55 (2015) 201-208.
doi:10.1016/j.jconrel.2017.03.318
Macrophage-mediated delivery of microparticles into tumor hypoxia zones Xuanrong Sun⁎, Longchao Zhang Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou 310006, China ⁎Corresponding author. E-mail address:
[email protected] (X. Sun) Macrophages, ubiquitous phagocytic cells in the human immune system, play a key role in homeostatic, immunological, and inflammatory processes. They are rapidly recruited to the diseased site by signaling molecules such as cytokines. Since macrophages play an indispensable role in most pathological conditions including cancer, atherosclerosis, various inflammatory diseases such as vasculitis and asthma, they represent an ideal target for therapeutic applications. Several approaches seeking to use macrophages for