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The feasibility of bacterial cellulose (BC) as a novel substrate for retinal pigment epithelium (RPE) culture was evaluated. Thin (41.6 ± 2.2 μm of average thickness) and heat-dried BC substrates were surface-modified via acetylation and polysaccharide adsorption, using chitosan and carboxymethyl cellulose. All substrates were characterized according to their surface chemistry, wettability, energy, topography, and also regarding their permeability, dimensional stability, mechanical properties, and endotoxin content. Then, their ability to promote RPE cell adhesion and proliferation in vitro was assessed. All surface-modified BC substrates presented similar permeation coefficients with solutes of up to 300 kDa. Acetylation of BC decreased it's swelling and the amount of endotoxins. Surface modification of BC greatly enhanced the adhesion and proliferation of RPE cells. All samples showed similar stress-strain behavior; BC and acetylated BC showed the highest elastic modulus, but the latter exhibited a slightly smaller tensile strength and elongation at break as compared to pristine BC. Although similar proliferation rates were observed among the modified substrates, the acetylated ones showed higher initial cell adhesion. This difference may be mainly due to the moderately hydrophilic surface obtained after acetylation. 2 ABSTRACT: The feasibility of bacterial cellulose (BC) as a novel substrate for retinal pigment epithelium (RPE) culture was evaluated. Thin (41.6 ± 2.2 µm of average thickness) and heatdried BC substrates were surface modified via acetylation and polysaccharide adsorption using chitosan and carboxymethyl cellulose. The BC substrates were characterized according to surface chemistry, wettability, energy, topography, permeability, dimensional stability, mechanical properties and level of endotoxins present. Then, the ability to promote RPE cell adhesion and proliferation in vitro was assessed. BC substrates were porous and permeable to solutes up to 300 kDa. The acetylation decreased substrate swelling and the amount of endotoxins present. Surface modification greatly enhanced the adhesion and proliferation of RPE cells in BC. Although similar proliferation rates were observed between the modified substrates, the acetylated ones showed higher initial cell adhesion. This difference may be mainly due to the moderately hydrophilic surface obtained after acetylation.

The concept of hip impingement and hip-preserving surgery has been appreciated in more detail since 2001 when a new surgical approach was reported and a hypothesis linking femoroacetabular impingement (FAI) with osteoarthritis was presented. Paralleling the introduction of hip arthroscopy, these events led to an increasing interest in the hip, and the number of publications has risen rapidly over the past 15 years, despite limited evidence levels and inconsistent methodology. Accordingly, etiology, diagnosis, prognosis, and the effects of treatment for FAI are still elusive due to a number of uncertainties and a lack of clear diagnostic criteria.Future research must focus on developing high-quality scientific studies, so thorough and reproducible methodology is needed. This review provides researchers, radiologists, and clinicians with a comprehensive approach to hip imaging with a focus on strategies to help guide the clinical diagnosis. Using evidence from current literature and knowledge from experienced clinicians, some of the imaging methodology challenges are deciphered.

The preparation of the (N,N'-diarylacetamidine)rhodium(III) complex in the cavities of zeolite Y is reported. The guest rhodium(III) complex was entrapped in the supercages of zeolite Y as a host by a two-step process in the liquid phase: (I) inclusion of rhodium(III) by ion-exchange in the structure and (II) introduction of N,N'-diarylacetamidine ligand followed by assembly of the complex inside the void space of the zeolite. The neat complex has also been prepared and characterized. The appropriate process selected for the in situ complex synthesis involved using an N,N'-diarylacetamidine ligand : rhodium(III) molar ratio of 4 : 1. Spectroscopic studies (Fourier transform infrared spectroscopy), chemical analyses, surface (X-ray photoelectron spectroscopy, scanning electron microscopy and X-ray diffraction) and cyclic voltammetric studies were used to characterize the new host-guest materials. Analysis of the data of the neat and encapsulated complex show that the coordination of the rhodium(III) ion (as a guest in the host structure) by the nitrogen atoms of the N,N'-diarylacetamidine ligand occurred in a 2 : 1 stoichiometry.

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