Browsing by Author "Piskin, Erhan"

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Citation - WoS: 16
Citation - Scopus: 15
Macroporous Silicone Biomaterials With Modified Surface Chemistry: Production and Characterization
(Sage Publications Ltd, 2012) Gencer, Zeynep A.; Odabas, Sedat; Sasmazel, Hilal T.; Piskin, Erhan
Porous and bioactive silicone biomaterials were developed for soft and cartilage tissue repair. A protocol, using compression molding, salt extraction, and supercritical carbon dioxide treatments, was used to obtain disk-shaped materials with specific pore sizes and morphologies by changing the process conditions. Highly open/interconnected macroporous silicone matrices, with an average pore size of 250-300 mu m and porosities in the range of 60%-70%, were obtained by the extracting the NaCl particles. Subsequent treatment with supercritical carbon dioxide slightly decreased the average pore size but increased the porosity to 80%. The supercritical carbon dioxide treatment effectively removed the entrapped salt crystals from the silicone matrix that improved interconnectivity. The compression modulus decreased, while the compression strength was increased using this technique. The surfaces and pores of the silicone materials were modified by silanization to provide primary amine groups for cell attachment, proliferation, migration, and three-dimensional growth of model L929 fibroblast cells.
Citation - WoS: 24
Citation - Scopus: 27
The Pimpled Gold Nanosphere: a Superior Candidate for Plasmonic Photothermal Therapy
(Dove Medical Press Ltd, 2020) Nasseri, Behzad; Turk, Mustafa; Kosemehmetoglu, Kemal; Kaya, Murat; Piskin, Erhan; Rabiee, Navid; Webster, Thomas J.
Background: The development of highly efficient nanoparticles to convert light to heat for anti-cancer applications is quite a challenging field of research. Methods: In this study, we synthesized unique pimpled gold nanospheres (PGNSs) for plasmonic photothermal therapy (PPTT). The light-to-heat conversion capability of PGNSs and PPTT damage at the cellular level were investigated using a tissue phantom model. The ability of PGNSs to induce robust cellular damage was studied during cytotoxicity tests on colorectal adenocarcinoma (DLD-1) and fibroblast cell lines. Further, a numerical model of plasmonic (COMSOL Multiphysics) properties was used with the PPTT experimental assays. Results: A low cytotoxic effect of thiolated polyethylene glycol (SH-PEG400-SH-) was observed which improved the biocompatibility of PGNSs to maintain 89.4% cell viability during cytometry assays (in terms of fibroblast cells for 24 hrs at a concentration of 300 mu g/mL). The heat generated from the nanoparticle-mediated phantom models resulted in Delta T=30 degrees C, Delta T=23.1 degrees C and Delta T=21 degrees C for the PGNSs, AuNRs, and AuNPs, respectively (at a 300 mu g/mL concentration and for 325 sec). For the in vitro assays of PPTT on cancer cells, the PGNS group induced a 68.78% lethality (apoptosis) on DLD-1 cells. Fluorescence microscopy results showed the destruction of cell membranes and nuclei for the PPTT group. Experiments further revealed a penetration depth of sufficient PPTT damage in a physical tumor model after hematoxylin and eosin (H&E) staining through pathological studies (at depths of 2, 3 and 4 cm). Severe structural damages were observed in the tissue model through an 808-nm laser exposed to the PGNSs. Conclusion: Collectively, such results show much promise for the use of the present PGNSs and photothermal therapy for numerous anti-cancer applications.