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In the current study, we successfully prepared chitosan/gelatin composite scaffolds reinforced by centrifugally spun polylactic acid (PLA) chopped nano/microfibers (PLA-CFs). Herein, different amounts of PLA-CFs (0 %, 1 %, 2 %, 3 %, and 4 % w/v) dispersed in chitosan/gelatin solution were used. Morphological characterization of prepared scaffolds revealed that at the initial stage of adding PLA-CFs, the chopped fibers were localized at the wall of the pores; however, as the fiber load increased, aggregations of chopped-fibers could be seen. Also, mechanical evaluation of scaffolds in terms of compression and tensile mode showed that samples reinforced with 2 % PLA-CFs had enhanced mechanical properties. Indeed, its tensile strength increased from 123.8 to 247.2 kPa for dry and 18.9 to 48.6 kPa for wet conditions. Furthermore, the tensile modulus associated with both conditions increased from 2.99 MPa and 44.5 kPa to 6.43 MPa and 158.4 kPa, respectively. The results of cell culture studies also confirmed that the prepared composite scaffold exhibited appropriate biocompatibility, cell proliferation and migration. The cell infiltration study of the samples revealed that scaffolds reinforced with 2 % PLA-CFs had significantly better cell penetration and distribution compared with the control ones on both days (7 and 14).

Treatment of non-healing skin wounds infected with extensively drug-resistant (XDR) bacteria remains as a big challenge. To date, different biomaterials have been applied for treatment of post-wound infections, nevertheless their efficacy for treatment of the wounds infected with XDR isolates has not been determined yet. In this study, the potential of the thermo-responsive chitosan (TCTS) hydrogel for protection of full-thickness wounds XDR bacteria isolated from burn patients was evaluated both in vitro and in vivo in a rat model. Antibacterial activity of the TCTS hydrogel against standard strain and clinical isolates of Acinetobacter baumannii, cytobiocompatibility for Hu02 fibroblast cells, degradation rate and swelling ratio were determined in vitro. MTT assay and disk diffusion test indicated no detectable cytotoxicity and antibacterial activity in vitro, respectively. In vivo study showed significant acceleration of wound healing, re-epithelialization, wound closure, and decreased colony count in the TCTS hydrogel group compared with control. This study suggests TCTS hydrogel as an excellent wound dressing for management of the wounds infected with XDR bacteria, and now promises to proceed with clinical investigations.

This research aimed to design innovative therapeutic bio-composites that enhance odontogenic and osteogenic differentiation of human dental pulp-derived mesenchymal stem cells (h-DPSCs) in-vitro regeneration. Herein, we report the fabrication of scaffolds containing chitosan, Ca-SAPO-34 monometallic and/or Fe-Ca-SAPO-34 bimetallic nanoparticles by freeze-drying technique. The scaffolds and nanoparticles were characterized using ICP-AES, FT-IR, XRD, TGA, TEM, BET, SEM, and EDS methods. The effects of SAPO-34 and nanoparticles were investigated by changes on the physicochemical properties of scaffolds including swelling ratio, density, porosity, bio-degradation, mechanical behavior, and biomineralization. Cell viability, cell adhesion and cytotoxicity of Ca-SAPO-34/CS and Fe-Ca-SAPO-34 scaffolds were investigated by MTT assay and SEM on h-DPSCs which revealed cell proliferation no toxicity on scaffolds. Cell tests demonstrated that Ca-SAPO-34/CS scaffold clearly displayed a positive effect on differentiation of hDPSCs into osteogenic/odontogenic cells and moderate effect on cell proliferation. Moreover, the incorporation of Fe2O3 to Ca-SAPO-34/CS scaffold promoted the proliferation of hDPSCs and osteogenic differentiation. Alizarin red, Alkaline phosphatase and QRT-PCR results showed that Fe-Ca-loaded SAPO-34/CS can lead to osteoblast/odontoblast differentiation in DPSCs through the up-regulation of related genes, thus indicating that Fe-Ca-SAPO-34/CS has remarkable prospects as a biomaterial for hard tissue engineering.

In this study, we synthesized thermo-responsive chitosan (TCTS) hydrogels, and loaded with different concentrations of antimicrobial peptide (AMP) (0, 4, 8 and 16 μg·ml−1) to fabricate an antibacterial wound dressing against resistant clinical isolates. Physico-chemical properties, release behavior, cytobiocompatibility and antibacterial activity of the AMP-TCTS hydrogels against standard strain and resistant Acinetobacter baumannii were fully determined in vitro. The TCTS-40% β-glycerolphosphate hydrogels showed a gelation time of 15 min at 37 °C. 80% weight loss at day 35 with no changes in pH value was observed. AMP-TCTS hydrogels showed a burst release of AMP (around 40%) at day 1, and a controlled release up to day 7. A dramatic water uptake was observed at first 4 h, and then continued for 10 h in a steady manner. All the AMP-TCTS hydrogels showed excellent cytobiocompatibility for human fibroblasts. The TCTS showed no antibacterial activity against both standard strain and clinical isolates. All the AMP-TCTS hydrogels had strong antibacterial activity against standard strains, but only 16 μg·ml−1 showed antibacterial behavior against resistant A. baumannii. Our results strongly suggest the 16 μg·ml−1 AMP-TCTS hydrogel as an excellent antibacterial wound dressing against resistant A. baumannii, and now promises to proceed with pre-clinical investigations.

Diabetic nephropathy as a deleterious complication of diabetes mellitus and an important cause of end-stage renal failure is characterized by changes in the molecular and cellular levels. Cell-cell communication via the gap and tight junctions are involved in the pathogenesis of diseases such as diabetes and kidney failure. Studying cell junctions including gap junctions, tight junctions, and anchoring junctions within the nephron can be used as an early sign of diabetic nephropathy. Furthermore, cell junctions may be an upcoming target by pharmacological methods to improve treatments of diabetic nephropathy and pave the way to introduce promising therapeutic strategies based on cell-cell communications effects and its translation into clinical studies for the treatment of diabetic nephropathy.

Chitosan as a biopolymer is an attractive vehicle for biomedical applications due to its unique characteristics. In order to improve chitosan's physicochemical features, chemical modification has been carried out to make it more suitable for such approaches. The aim of this study was to prepare and evaluate thiolated chitosan-lauric acid as a new chitosan derivative for biomedical use. Lauric acid was introduced to chitosan via stable amide bond between carboxylic acid group of fatty acid and the amine in the chitosan and thiolation was carried out using thioglycolic acid. Resulted polymers were characterized by FTIR, 1H NMR and TGA. Moreover, cell viability assessment of new derivative was performed using MTT method. FTIR and 1H NMR results showed that both substitution reactions were successfully completed. Furthermore, new synthesized polymer had no significant cytotoxicity against normal gingiva human cells (HGF1-PI 1).These findings confirm that this new derivative can be introduced as a suitable polymer for biomedical purposes such as mucosal drug delivery.

Non-invasive diagnosis of cancer is often the key to effective treatment and patient survival. Saliva as a multi-constituent oral fluid comprises various disease signaling biomarkers, holds great potential for early-stage cancer diagnostics with cost-effective and easy collection, storage, transport and processing. Therefore, detection of biomarkers and proteins in the saliva samples is highly demand. The current review was performed using reliable internet database (mainly PubMed) to provide an overview of the most recent developments on non-invasive diagnosis of cancers in saliva and highlights main challenges and future prospects in sensing of the salivary biomarkers. The conventional detection methods of cancer biomarkers in saliva is discussed in the paper, however, the main focus is on non-invasive diagnosis of cancers in saliva using immunosensing (electrochemical, optical, piezoelectric), DNA based sensors, aptasensors and peptide based bio-assays The reviewed literature revealed that non-invasive cancer detection methods using the mentioned biosensors and without any processing of saliva sample offers a quick, sensitive, specific and cost effective analytical tool. Besides, salivary based detection methods can be used for simultaneous detection of panels of disease specific biomarkers in a real time manner or as home testing kits in near future.

In this work, for the first time, we presented a novel design strategy to fabricate a new type of Octa-aminopropyl polyhedral oligomeric silsesquioxane hydrochloride salt (OA-POSS)-based Alg/PAAm DN gels, consisting of PAAm gel as the first chemical network and Alg/OA-POSS gel as the second chemical-physical network. Incorporation of OA-POSS nanoparticles with various feed ratio into the second network not only led to form strong coordination interactions but also in comparison to the other Alg/PAAm gels demonstrated superior mechanical properties. pH, temperature, contact time and salt effects parameters were studied on the swelling and dye removal properties of the synthesized DN hybrid hydrogels. The adsorption experiments exhibited that 20 mg of Alg/PAAm/OA-POSS1 showed the maximum adsorption capacity for methylene blue (MB) at pH 9 and 11. Dye adsorption kinetics were modeled by the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic equations under different conditions. Additionally, adsorption isotherms of the adsorption of MB were analyzed.

The accurate quantification of the level of breast cancer specific protein CA 15-3 in serum is crucial for cancer prognosis. This work, a novel and sensitive label-free immunoassay based on gold nanospear (Au NSs) electrochemically assembled onto thiolated graphene quantum dots (CysA/GQDs) for the detection of CA 15-3 antibodies. The CysA/Au NSs/GQDs hybrid interface provides a large surface area for the effective immobilization of CA 15-3 antigens, as well as it ascertains the bioactivity and stability of immobilized CA 15-3 antigens. Field emission scanning electron microscope (FE-SEM), and EDS photoelectron spectroscopies were used to monitor the sensor fabrication. Also, cyclic voltammetry was used to quantify the extent of Au NSs' surface coverage by CA 15-3 antigens. Square wave voltammetry (SWV) was employed to investigate the immunosensor fabrication and to monitor the binding events between CA 15-3 antigens-antibodies. Under optimized experimental conditions, the immunosensor displayed good sensitivity and specificity. The CA 15-3 were detected in a concentration as low as 0.11U/mL with a linear range from 0.16-125U/mL. The high sensitivity of the immunosensor may derive from the high loading of CA 15-3 antibodies on CysA/Au NSs/GQDs hybrid interface which increases the number of binding events. The method was successfully applied assay of the CA 15-3 in unprocessed human plasma samples. Also, proposed immunosensor was applied to the assay of CA 15-3 malignant cell line lysates (human breast adenocarcinoma cell line-MCF-7).