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In the recent years, electroconductive scaffolds have shown promising capabilities in guided regeneration of electroactive tissues including nerve, heart muscle, bone, cartilage, and skin. Herein, the fabrication of a novel electroconductive poly (L‐lactic acid) (PLLA)/polyamidoamine (PAMAM) dendrimer nanofibrous scaffold containing graphene oxide (GO) nanosheets is described. The presence of PAMAM with amine terminal groups successfully aminolyzed PLLA. Interestingly, both PAMAM (5% w/w) and GO (0.5, 1, 2% w/w) not only contributed to reducing the fiber diameter, increasing the hydrophilicity and degradation rate, but also provided a nanocomposite scaffold with enhancement in electrical conductivity. By incorporating 1% w/w of GO, the nanocomposite scaffold exhibited optimized properties, including electrical conductivity (≈3.09 × 10−5 S m−1), crystallinity (≈ 47%), Young's modulus (≈16.95 MPa), as well as strength (≈1.58 MPa). This nanocomposite also demonstrated significant antibacterial activity of ≥ 90% against both gram‐positive and gram‐negative bacteria. Cellular assays confirmed acceptable cytocompatibility of the nanocomposite scaffolds containing GO and PAMAM, which can support the viability and proliferation of PC‐12 cells. In conclusion, the presence of GO nanosheets alongside PAMAM dendrimers can synergically promote the properties of the prepared nanofibrous mats which can be used as potential electroconductive scaffolds for guided tissue regeneration. The study presents the fabrication of a PLLA‐based nanocomposite scaffold containing PAMAM dendrimer and GO nanosheets utilizing the electrospinning technique. The nanocomposite scaffold shows significantly higher electrical conductivity, wettability, and mechanical properties, while further demonstrating favorable cellular behavior and antibacterial activity comparable to the neat PLLA. This nanocomposite is a promising scaffold superior to existing PLLA fibrous substates for guided tissue regeneration.

An injectable hybrid hydrogel is synthesized, comprising silk fibroin (SF) and chondroitin sulfate (CS) through di‐tyrosine formation bond of SF chains. CS and SF are reported with excellent biocompatibility as tissue engineering scaffolds. Nonetheless, the rapid degradation rate of pure CS scaffolds presents a challenge to effectively recreate articular cartilage. As CS is one of the cartilage extracellular matrix (ECM) components, it has the potential to enhance the biological activity of SF‐based hydrogel in terms of cartilage repair. Therefore, altering the CS concentrations (i.e., 0 wt%, 0.25 wt%, 0.5 wt%, 1 wt%, and 2 wt%), which are interpenetrated between SF β‐sheets and chains, can potentially adjust the physical, chemical, and mechanical features of these hybrid hydrogels. The formation of β‐sheets by 30 days of immersion in de‐ionized (DI) water can improve the compression strength of the SF/CS hybrid hydrogels in comparison with the same SF/CS hybrid hydrogels in the dried state. Biological investigation and observation depicts proper cell attachment, proliferation and cell viability for C28/I2 cells. Gene expression of sex‐determining region YBox 9 (SOX9), Collagen II α1, and Aggrecan (AGG) exhibits positive C3H10T1/2 growth and expression of cartilage‐specific genes in the 0.25 wt% and 0.5 wt% SF/CS hydrogels. In the current study, an injectable hybrid hydrogel containing silk fibroin (SF) and chondroitin sulfate (CS) is prepared and characterized through di‐tyrosine formation bonds between SF chains using horse radish peroxide (HRP) and hydrogen peroxide (H2O2). In fact, altering CS amounts, which are interpenetrated between SF β‐sheets and chains adjusts the physical, chemical, and biological features of these hybrid hydrogels.

Purpose: Pennyroyal is a species of the Lamiaceae family with potent anti-cancer and antioxidant properties. Combining this antioxidant with chemotherapeutic agents enhances the effectiveness of these agents by inducing more apoptosis in cancerous cells. Methods: Here, methotrexate (MTX) combined with pennyroyal oil based on PEGylated nanostructured lipid carriers (NLCs) was assessed. These nanoparticles were physiochemically characterized, and their anti-cancer effects and targeting efficiency were investigated on the folate receptor-positive human breast cancer cell line (MCF-7) and negative human alveolar basal epithelial cells (A549). Results: Results showed a mean size of 97.4±12.1 nm for non-targeted PEGylated NLCs and 220.4±11.4 nm for targeted PEGylated NLCs, with an almost small size distribution assessed by TEM imaging. Furthermore, in vitro molecular anti-cancer activity investigations showed that pennyroyal-NLCs and pennyroyal-NLCs/MTX activate the apoptosis and autophagy pathway by changing their related mRNA expression levels. Furthermore, in vitro cellular studies showed that these changes in the level of gene expression could lead to a rise in apoptosis rate from 15.6±8.1 to 25.0±3.2 (P<0.05) for the MCF-7 cells treated with pennyroyal-NLCs and pennyroyal-NLCs/MTX, respectively. Autophagy and reactive oxygen species (ROS) cellular evaluation indicated that treating the cells with pennyroyal-NLCs and pennyroyal-NLCs/MTX could significantly increase their intensity in these cells. Conclusion: Our results present a new NLCs-based approach to enhance the delivery of pennyroyal and MTX to cancerous breast tissues.

This paper aims to review the State of the Art in metal self-expanding stents made from nitinol (NiTi), showing shape memory and superelastic behaviors, to identify the challenges and the opportunities for improving patient outcomes. A significant contribution of this paper is its extensive coverage of multidisciplinary aspects, including design, simulation, materials development, manufacturing, bio/hemocompatibility, biomechanics, biomimicry, patency, and testing methodologies. Additionally, the paper offers in-depth insights into the latest practices and emerging trends, with a special emphasis on the transformative potential of additive manufacturing techniques in the development of metal stents. By consolidating existing knowledge and highlighting areas for future innovation, this review provides a valuable roadmap for advancing nitinol stents.

This work aimed to determine the physicochemical and biochemical properties of trypsin from beluga Huso huso and sevruga Acipenser stellatus, two highly valuable sturgeon species. According to the results obtained from the methods of casein-zymogram and inhibitory activity staining, the molecular weight of trypsin for sevruga and beluga was 27.5 and 29.5 kDa, respectively. Optimum pH and temperature values for both trypsins were recorded at 8.5 and 55 °C by BAPNA (a specific substrate), respectively. The stability of both trypsins was well-preserved at pH values from 6.0 to 11.0 and temperatures up to 50 °C. TLCK and SBTI, two specific trypsin inhibitors, showed a significant inhibitory effect on the enzymatic activity of both trypsins (p < 0.05). The enzyme activity was significantly increased in the presence of Ca+2 and surfactants and decreased by oxidizing agents, Cu+2, Zn+2, and Co+2 (p < 0.05). However, univalent ions Na+ and K+ did not show any significant effect on the activity of both trypsins (p > 0.05). The results of our study show that the properties of trypsin from beluga and sevruga are in agreement with data reported in bony fish and can contribute to the clear understanding of trypsin activity in these primitive species.

In the present study, an antibacterial nanofibrous wound dressing from a combinatory composition of silk fibroin and graphene oxide (GO) is fabricated, evaluated and optimized. Fibroin was extracted from silkworm cocoons and GO was synthesized from graphite precursor, according to the modified Hummers’ method. Later on, different compositions with varying content of GO ranging from 0 to 0.024 % w/w were electrospun and comprehensively evaluated by electron microscopy, mechanical testing, swelling measurement, water vapor transmission, cell culture and antibacterial analysis. SEM micrographs showed a defect-free fibrous morphology with an average fiber diameter in the range of 169–301 nm. Uniaxial tension experiments revealed that with the inclusion of GO to formulation up to 0.016 % w/w GO, tensile properties were improved. Incorporation of hydrophilic GO nanosheets in the fibroin fibers also resulted in improving contact angle, water swelling and water vapor transmittance characteristics with an optimized value of 80±5.36±1 % and 80±2.5 g/m2h, respectively. The cell culture study corroborated the appropriate cell proliferation and morphology on the fibroin/GO fibers, particularly with 0.016 % w/w GO content. And finally, antibacterial evaluation of the nanocomposite with optimized GO content confessed the anti-bacterial activity of the prepared dressing.

Magnesium (Mg)-based alloys are biodegradable metallic biomaterials that show promise in minimizing the risks of permanent metallic implants. However, their clinical applications are restricted due to their rapid in vivo degradation and low surface hemocompatibilities. Surface modifications are critically important for controlling the corrosion rates of Mg-based alloys and improving their hemocompatibilities. In the present study, two heparinization methods were developed to simultaneously increase the corrosion resistance and hemocompatibility of the AZ31 Mg alloy. In the first method, the surface of the AZ31 alloy was modified by alkali–heat treatment and then aminolyzed by 3-amino propyltriethoxy silane (APTES), a self-assembly molecule, and heparin was grafted onto the aminolyzed surface. In the second method, before heparinization, polyamidoamine dendrimers (PAMAM4-4) were grafted onto the aminolyzed surface with APTES to increase the number of surface functional groups, and heparinization was subsequently performed. The presence of a peak with a wavelength of about 1560 cm−1 in the FTIR spectrum for the sample modified with APTES and dendrimers indicated aminolysis of the surface. The results indicated that the corrosion resistance of the Mg alloy was significantly improved as a result of the formation of a passive layer following the alkali–heat treatment. The results obtained from a potentiodynamic polarization (PDP) test showed that the corrosion current in the uncoated sample decreased from 25 µA to 3.7 µA in the alkali–heat-treated sample. The corrosion current density was reduced by 14 and 50 times in samples treated with the self-assembly molecules, APTES and dendrimers, respectively. After heparinization, the clotting time for pristine Mg was greatly improved. Clotting time increased from 480 s for the pristine Mg sample to 630 s for the APTES- and heparin-modified samples and to 715 s for the PAMAM- and heparin-modified samples. Cell culture data showed a slight improvement in the cell-supporting behavior of the modified samples.

In this study, silk fibroin (SF) was extracted from the silkworm cocoon and fabricated to form a nonwoven mat by electrospinning process. In order to improve the electrospinnability of SF, the polymer solution was treated with atmospheric pressure plasma. Conductivity and viscosity of SF-formic acid solution increased after the plasma treatment. The morphology of SF electrospun scaffolds before and after treatment was investigated by scanning electron microscope (SEM). The results showed that plasma treatment significantly improved the electrospinnability of SF solution and the morphology became fine and bead-less. Furthermore, the results of the fourier-transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) showed that the plasma treatment increased the crystallinity of SF scaffolds and changed some part of polymer conformation from random coil to β-sheet crystals. Additionally, this method increased the mechanical properties and biodegradation resistance of SF scaffolds.

Electric fields are known to affect cell growth and viability. Using electric field treatments for cancer therapy and regenerative medicine is actively researched because of the noninvasive, efficient and low-price nature of electric field exposure. To monitor the effects of such treatments on cells, chemical assays are conventionally used after treatment which are usually time-consuming, expensive, offline and destructive to the sample under study. Electric cell impedance sensing has recently been shown to provide comparable monitoring capability for chemical treatments nondestructively. Here, we report a novel device that provides electric field treatment with online cell-substrate impedance sensing, both combined through a single microelectrode array. Design, numerical simulations and dosimetry, microfabrication and in vitro tests are described, and the electronic systems realized to flexibly control electric field exposure amplitude and timings are explained. The fast, nondestructive performance of the resulting stimulus–ECIS system is successfully confirmed in comparison with chemical assays. Also a real experiment is reported showing the prevention of cancerous cell growth by 26% with exposure to a weak EF at 150 kHz frequency. The fast, online response of the device signifies its potential to become a popular standard setup for experimental cell research.

There is a myriad of ways to crosslink hydrogel wound dressings; however, they require additional steps to remove the residue of the crosslinking agents, or their byproducts in biological environments are toxic. In this study, we studied and characterized the crosslinking of the chitosan hydrogels by various dicarboxylic acids, including oxalic acid, adipic acid, and sebacic acid under vacuum at 90 °C. The concentrations of the crosslinkers in the crosslinked hydrogels are tolerable for the cells, and the membranes can be used after crosslinking without complicated additional steps to remove the unreacted residues. The molar ratio of the crosslinkers was calculated based on the stoichiometry of the chitosan amine groups. Attenuated total reflectance Fourier transform infrared spectroscopy revealed amide linkage formation between amine groups of the chitosan and carboxyl groups of the dicarboxylic acids at 90 °C. The results showed that the chitosan membranes crosslinked with oxalic acid had higher Young's modulus (~ 1042 N/mm 2 ) and ultimate tensile strength (~ 75 N/mm 2 ) in comparison with the other dicarboxylic acids. Moreover, the membranes crosslinked with oxalic acid showed a weight loss of ~ 5.4% after 24 h at double-distilled water, which was drastically lower than that of the others. Thus, oxalic acid was selected as the most effective crosslinker. Cell viability assay, using mouse fibroblast (L929) cells, was conducted on the mechanically optimized membranes. The fibroblast cells successfully attached and spread well on the surface of the membranes. In conclusion, the obtained results suggested oxalic acid as an effective and non-toxic crosslinker for chitosan-based membranes for wound dressing applications. Graphic abstract