Browsing by Subject "Epitopes"

Now showing 1 - 2 of 2

Open Access
Bioactive peptide functionalized aligned cyclodextrin nanofibers for neurite outgrowth
(Royal Society of Chemistry, 2017) Hamsici, S.; Cinar, G.; Celebioglu A.; Uyar, Tamer; Tekinay, A. B.; Güler, Mustafa O.
Guidance of neurite extension and establishment of neural connectivity hold great importance for neural tissue regeneration and neural conduit implants. Although bioactive-epitope functionalized synthetic or natural polymeric materials have been proposed for the induction of neural regeneration, chemical modifications of these materials for neural differentiation still remain a challenge due to the harsh conditions of chemical reactions, along with non-homogeneous surface modifications. In this study, a facile noncovalent functionalization method is proposed by exploiting host-guest interactions between an adamantane-conjugated laminin derived bioactive IKVAV epitope and electrospun cyclodextrin nanofibers (CDNFs) to fabricate implantable scaffolds for peripheral nerve regeneration. While electrospun CDNFs introduce a three-dimensional biocompatible microenvironment to promote cellular viability and adhesion, the bioactive epitopes presented on the surface of electrospun CDNFs guide the cellular differentiation of PC-12 cells. In addition to materials synthesis and smart functionalization, physical alignment of the electrospun nanofibers guides the cells for enhanced differentiation. Cells cultured on aligned and IKVAV functionalized electrospun CDNFs had significantly higher expression of neuron-specific βIII-tubulin and synaptophysin. The neurite extension is also higher on the bioactive aligned scaffolds compared to random and non-functionalized electrospun CDNFs. Both chemical and physical cues were utilized for an effective neuronal differentiation process. © The Royal Society of Chemistry.
Open Access
Inhibition of VEGF mediated corneal neovascularization by anti-angiogenic peptide nanofibers
(Elsevier, 2016-11) Senturk, B.; Cubuk, M. O.; Ozmen, M. C.; Aydin B.; Güler, Mustafa O.; Tekinay, A. B.
Atypical angiogenesis is one of the major symptoms of severe eye diseases, including corneal neovascularization, and the complex nature of abnormal vascularization requires targeted methods with high biocompatibility. The targeting of VEGF is the most common approach for preventing angiogenesis, and the LPPR peptide sequence is known to strongly inhibit VEGF activity by binding to the VEGF receptor neuropilin-1. Here, the LPPR epitope is presented on a peptide amphiphile nanofiber system to benefit from multivalency and increase the anti-angiogenic function of the epitope. Peptide amphiphile nanofibers are especially useful for ocular delivery applications due to their ability to remain on the site of interest for extended periods of time, facilitating the long-term presentation of bioactive sequences. Consequently, the LPPR sequence was integrated into a self-assembled peptide amphiphile network to increase its efficiency in the prevention of neovascularization. Anti-angiogenic effects of the peptide nanofibers were investigated by using both in vitro and in vivo models. LPPR-PA nanofibers inhibited endothelial cell proliferation, tube formation, and migration to a greater extent than the soluble LPPR peptide in vitro. In addition, the LPPR-PA nanofiber system led to the prevention of vascular maturation and the regression of angiogenesis in a suture-induced corneal angiogenesis model. These results show that the anti-angiogenic activity exhibited by LPPR peptide nanofibers may be utilized as a promising approach for the treatment of corneal angiogenesis.