Magnetic carboxymethyl cellulose-silk fibroin hydrogel: A ternary nanobiocomposite exhibiting excellent biological activity and in vitro hyperthermia of cancer therapy.

In this work, a magnetic nanobiocomposite scaffold based on carboxymethylcellulose (CMC) hydrogel, silk fibroin (SF), and magnetite nanoparticles was fabricated. The structural properties of this new magnetic nanobiocomposite were characterized by various analyses such as FT-IR, XRD, EDX, FE-SEM, TGA and VSM. According to the particle size histogram, most of the particles were between 55 and 77 nm and the value of saturation magnetization of this nanobiocomposite was reported 41.65 emu.g- 1. Hemolysis and MTT tests showed that the designed magnetic nanobiocomposite was compatible with the blood. In addition, the viability percentage of HEK293T normal cells did not change significantly, and the proliferation rate of BT549 cancer cells decreased in its vicinity. EC50 values for HEK293T normal cells after 48 h and 72 h were 3958 and 2566, respectively. Also, these values for BT549 cancer cells after 48 h and 72 h were 0.4545 and 0.9967, respectively. The efficiency of fabricated magnetic nanobiocomposite was appraised in a magnetic fluid hyperthermia manner. The specific absorption rate (SAR) of 69 W/g (for the 1 mg/mL sample at 200 kHz) was measured under the alternating magnetic field (AMF).

A novel magnetic nanocomposite based on alginate-tannic acid hydrogel embedded with silk fibroin with biological activity and hyperthermia application.

In the current study, sodium alginate (SA) and tannic acid (TA), in the presence of calcium chloride as a cross-linker, were used to fabricate a nanocomposite scaffold. With the addition of silk fibroin (SF), the strength of the synthesized composite was increased. Fe3O4 magnetic nanoparticles (MNPs) led to the usage of this magnetic nanocomposite in hyperthermia applications. Various properties of this scaffold were investigated by field emission scanning electron microscope (FE-SEM), thermogravimetric analysis (TGA), Fourier-transformed infrared (FT-IR), energy dispersive X-Ray (EDX), Vibrating- sample magnetometer (VSM). A hemolytic assay of this magnetic nanocomposite demonstrated that about 100 % of red blood cells (RBCs) survived at a concentration of 2 mg/ml, proving this scaffold is hemocompatible. Furthermore, an MTT assay was utilized to assess the cytotoxicity of the synthesized magnetic nanocomposite. Finally, the hyperthermia behavior of the fabricated magnetic nanocomposite was evaluated, and the specific absorption rate (SAR) was 73.53 W/g. The proposed nanocomposite is a good candidate for wound dressing applications in future studies.

Recent advances on biomedical applications of pectin-containing biomaterials.

There is a growing demand for biomaterials developing with novel properties for biomedical applications hence, hydrogels with 3D crosslinked polymeric structures obtained from natural polymers have been deeply inspected in this field. Pectin a unique biopolymer found in the cell walls of fruits and vegetables is extensively used in the pharmaceutical, food, and textile industries due to its ability to form a thick gel-like solution. Considering biocompatibility, biodegradability, easy gelling capability, and facile manipulation of pectin-based biomaterials; they have been thoroughly investigated for various potential biomedical applications including drug delivery, wound healing, tissue engineering, creation of implantable devices, and skin-care products.

Green synthesis and evaluation of silver nanoparticles as adjuvant in rabies veterinary vaccine.

BACKGROUND: Green synthesis of nanoparticles by plant extracts plays a significant role in different applications. Recently, several studies were conducted on the use of nanoparticles as adjuvant. The main aim of this study was to evaluate green synthesized silver nanoparticles (AgNPs) as adjuvant in rabies veterinary vaccine and compare the results with the existing commercially available alum adjuvant. MATERIALS AND METHODS: In the current study, AgNPs were prepared by the reduction of aqueous silver nitrate by leaf extract of Eucalyptus procera. The formation of AgNPs was confirmed by ultraviolet (UV)-visible spectrophotometer, scanning electron microscopy, dynamic light scattering, and X-ray diffraction analysis. Then, different amounts of AgNPs (200 µg, 400 µg, 600 µg, and 800 µg) were added to 1 mL of inactivated rabies virus. The loaded vaccines (0.5 mL) were injected intraperitoneally into six Naval Medical Research Institute mice in each group on days 1 and 7. On the 15th day, the mice were intracerebrally challenged with 0.03 mL of challenge rabies virus (challenge virus strain-11, 20 lethal dose [20 LD50]), and after the latency period of rabies disease in mice (5 days), the mice were monitored for 21 days. Neutralizing antibodies against rabies virus were also investigated using the rapid fluorescent focus inhibition test method. The National Institutes of Health test was performed to determine the potency of optimum concentration of AgNPs as adjuvant. In vitro toxicity of AgNPs was assessed in L929 cell line using MTT assay. In addition, in vivo toxicity of AgNPs and AgNPs-loaded vaccine was investigated according to the European Pharmacopeia 8.0. RESULTS: AgNPs were successfully synthesized, and the identity was confirmed by UV-visible spectrophotometry and X-ray diffraction analysis. The prepared AgNPs were spherical in shape, with an average size of 60 nm and a negative zeta potential of -14 mV as determined by dynamic light scattering technique. The highest percentage of viability was observed at 15 mg/kg and 20 mg/kg of AgNPs-loaded vaccine concentrations after injecting into the mice. The calculated potencies for alum-containing vaccine and AgNPs-loaded vaccine (dose 15 mg/kg) were 1.897 and 1.303, respectively. MTT assay demonstrated that alum at the concentration of 10 mg/mL was toxic, but AgNPs were not toxic. The in vivo toxicity also elucidated the safety of AgNPs and AgNPs-loaded vaccine in mice and dogs, respectively. CONCLUSION: In the current study, for the first time, the adjuvanticity effect of green synthesized AgNPs on veterinary rabies vaccine potency with no in vivo toxicity was elucidated according to the European Pharmacopeia 8.0.