Design of hybrid gels based on gellan-cholesterol derivative and P90G liposomes for drug depot applications

Gels are extensively studied in the drug delivery field because of their potential benefits in therapeutics. Depot gel systems fall in this area, and the interest in their development has been focused on long-lasting, biocompatible, and resorbable delivery devices. The present work describes a new class of hybrid gels that stem from the interaction between liposomes based on P90G phospholipid and the cholesterol derivative of the polysaccharide gellan. The mechanical properties of these gels and the delivery profiles of the anti-inflammatory model drug diclofenac embedded in such systems confirmed the suitability of these hybrid gels as a good candidate for drug depot applications

Preparation of gellan-cholesterol nanohydrogels embedding baicalin and evaluation of their wound healing activity

[EN] In the present work, the preparation, characterization and therapeutic potential of baicalin-loaded nanohydrogels are reported. The nanohydrogels were prepared by sonicating (S nanohydrogel) or autoclaving (A nanohydrogel) a dispersion of cholesterol-derivatized gellan in phosphate buffer. The nanohydrogel obtained by autoclave treatment showed the most promising results: smaller particles ( similar to 362 nm vs. similar to 530 nm), higher homogeneity (polydispersity index = similar to 0.24 vs. similar to 0.47), and lower viscosity than those obtained by sonication. In vitro studies demonstrated the ability of the nanohydrogels to favour the deposition of baicalin in the epidermis. A high biocompatibility was found for baicalin-loaded nanohydrogels, along with a great ability to counteract the toxic effect induced by hydrogen peroxide in cells, as the nanohydrogels re-established the normal conditions (similar to 100% viability). Further, the potential of baicalin-loaded nanohydrogels in skin wound healing was demonstrated in vivo in mice by complete skin restoration and inhibition of specific inflammatory markers (i.e., myeloperoxidase, tumor necrosis factor-alpha, and oedema.Financial support from University "Sapienza" - Progetti di Ricerca: grant RP116154C2EF9AC8 and grant RM11715C1743EE89 are acknowledged.Manconi, M.; Manca, M.; Caddeo, C.; Cencetti, C.; Di Meo, C.; Zoratto, N.; Nácher Alonso, A.... (2018). Preparation of gellan-cholesterol nanohydrogels embedding baicalin and evaluation of their wound healing activity. European Journal of Pharmaceutics and Biopharmaceutics. 127:244-249. https://doi.org/10.1016/j.ejpb.2018.02.015S24424912

Optical scattering (TAOS) by tire debris particles: preliminary results

Tire debris particles from low severity laboratory wear tests have been investigated by the TAOS optical scattering facility at Yale University. The incident wavelength is 532 nm. After the TAOS event some particle samples have been imaged by a scanning electron microscope and microanalyzed. The TAOS intensity patterns recorded within a solid angle in the backward sector have been processed by cluster analysis and compared with the patterns computed by a T-matrix code. Preliminary agreement has been found between TAOS data and the particle models (size, shape, refractive index). The purpose of the investigation is to obtain signatures of the material, based on its TAOS pattern. © 2001 Optical Society of America

Preparation and characterization of a new gellan gum and sulphated hyaluronic acid hydrogel designed for epidural scar prevention

Postsurgical adhesions are a common problem in clinical practice, causing nerve compression, pain and discomfort. A new hydrogel based on gellan gum and sulphated hyaluronic acid was synthesized, with the aim to create an effective barrier for epidural scar formation. Physico-chemical properties of the gel were analyzed, and preliminary biocompatibility data (i.e. cytotoxicity) have been collected in view of its potential clinical use. The characterization of the new material demonstrated that the hydrogel, due to its high-viscosity, could effectively act as a barrier with a long in situ residence time. In addition, the hydrogel can be easily extruded from a syringe and its structure exhibits excellent stabilizing properties. Furthermore, biological assays showed that this gel is suitable for further preclinical development

Preparation and Characterization of Novel Gellan Gum Hydrogels Suitable for Modified Drug Release

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An in situ gelling system for bone regeneration of osteochondral defects

The aim of this study was the preparation of a very simple and, at the same time, innovative three-component in-situ gelling hydrogel, composed of hyaluronic acid, gellan gum and calcium chloride, for osteochondral defects reparation. The above mentioned biocompatible polymers were used in a smart combination for bone defects filling and capping, capable to form a very stable system that avoids the leakage of any material from it. The polymeric materials, obtained using various combinations of polymers/calcium ratios, were characterized in terms of rheological and dynamo-mechanical properties, degradation rate and adhesion to bone defects. In vitro biocompatibility tests, performed using human primary osteoblasts, showed that this novel system can be an ideal candidate for the regeneration of bone defects, potentially improving the surgery approach in this fiel