Design and Fabrication of Biodegradable Tissue Adhesive Using Albumin Nanoparticles and Polypyrrole as a Suture Substitute in Surgery and Trauma

Background and Aim: Tissue adhesives are increasingly used instead of sutures or staples to close wounds in modern medicine. It seems that use of tissue adhesives can lead to faster and easier closure of the surgical wounds in comparison to sutures. Moreover, tissue glues have a wide application in the fields of tissue engineering and drug delivery systems. Bio-glue which is a widely used bioadhesive in surgery contains bovine serum albumin and glutaraldehyde, but it has significant tissue toxicity due to the high percentage of glutaraldehyde. Adhesive biocompatibility may improve by using albumin nanoparticles along with less toxic cross-linkers such as polypyrrole. Materials and methods:  Albumin nanoparticles were prepared by coacervation method and then, polypyrrole and glutaraldehyde in different proportions were used to prepare the bioadhesive. The properties of nanoparticles were examined by DLS, zeta potential analysis, FT-IR spectrum, and scanning electron microscopy. The effects of pH and concentration of albumin nanoparticles on gelation time were analyzed and the cytotoxicity of the adhesive was investigated by the MTT technique. Results:  Among the prepared composites, the shortest gelation time was 20 seconds which belonged to the composite containing both crosslinking agents (pyrrole and glutaraldehyde 3%). The results of MTT assay showed that by reducing the percentage of glutaraldehyde, the toxicity of the adhesive significantly decreased (P <0.0001) compared to the toxicity of adhesive containing 10% glutaraldehyde. Conclusion: Adhesive prepared by use of polypyrrole and 3% glutaraldehyde had a shorter gelation time and greater biocompatibility than the adhesive containing 10% glutaraldehyde. Therefore, it has the potential to replace other adhesives in the medical clinics

Selective oxidation of sulfides and hydrocarbons with H2O2 over manganese catalyst supported on nanoparticles

University of ZanjanA new magnetically separable catalyst consisting of binuclear Mn(II) complex [Mn-2 (HL)(2) (H2O)(4)], HL = 2-[(2-hydroxy-benzylidene)-amino]-3-(4-hydroxyphenyl)-propionic acid, supported on (3-chloropropyl)-trimethoxysilane (CPTMS) functionalized silica-coated magnetic nanoparticles (MNPs) was prepared. The synthesized catalyst was characterized by several physico-chemical and spectroscopic methods. This immobilized complex was found to be an efficient heterogeneous catalyst for the oxidation of different sulfides and hydrocarbons using hydrogen peroxide (H2O2) as an oxidant. The catalyst is readily recovered by simple magnetic decantation and can be recycled several times with no considerable loss of catalytic activity

Influence of pore structural properties in metal-organic frameworks on the host-guest interaction in drug delivery

Properties of pore structure in Metal-organic frameworks (MOFs) play a key role in the adsorption of target molecules hence are used to improve the efficiency in MOFs. In this study, we synthesized three MOFs with different hydrophilicity, namely TMU-6(RL1), TMU-21(RL2) and TMU-59. Additionally, we studied the effect of hydrophobicity/hydrophilicity of pore in MOFs on the drug delivery and sensing properties. The structure of these frameworks was characterized by XPS, BET, XRD, IR and TG. The DLC and DLE of TMU-6(RL1), TMU-21(RL2) and TMU-59, were determined by (20%, 70%), (18%, 78%) and (3.6%, 13.6%), respectively. Also, the curcumin release reached 74%, 57% and 8% respectively for TMU-6(RL1), TMU-21(RL2) and TMU-59 after 100 h in PBS solution with pH 7.2 respectively. The carriers showed high adsorption efficiency and controlled release. Adsorption of curcumin as an anticancer drug to the MOFs was done through multiple mechanisms such as Hostπ–πGuest interaction and HostN–H⋯OGuest hydrogen bonds. Also, studies of in vitro anticancer revealed that the cytotoxicity of the MOFs@Curcumin composites against HT-29 cancer cells in MOFs was more than free curcumin. The findings demonstrated that the changes in the hydrophilic properties of frameworks can specifically control the Host-Guest interactions, drug loading and its release

Spectroscopic investigation on the interaction of DNA with superparamagnetic iron oxide nanoparticles doped with chromene via dopamine as cross linker

Objective(s): The interaction of DNA with iron oxide nanoparticles (SPIONs) was studied to find out the interaction mechanism and design new drug delivery systems. Materials and Methods: The interaction of calf thymus DNA (ctDNA) with SPIONs doped with 2H-chromene via dopamine as cross linker (SPIONs@DA-Chr) was studied using the UV absorption spectroscopy, viscosity measurement, circular dichroism, fluorescence and FT-IR spectroscopic techniques. Results: UV absorption study showed hyperchromic effect in the spectra of DNA. Few changes were observed in the viscosity of ctDNA in the presence of different concentration of SPIONs@DA-Chr. The result of circular dichroism (CD) suggested that SPIONs@DA-Chr can change the secondary structure of DNA. Further, fluorescence quenching reaction of ctDNA with SPIONs@DA-Chr and competitive fluorescence spectroscopy studied by using methylene blue, have shown that the SPIONs@DA-Chr can bind to ctDNA through non-intercalative mode. FT-IR spectroscopy confirmed the binding of SPIONs@DA-Chr and ctDNA. Conclusion: These results suggested that SPIONs@DA-Chr binds to DNA via groove binding mode

Purified compounds from marine organism sea pen induce apoptosis in human breast cancer cell MDA-MB-231 and cervical cancer cell HeLa

Marine organisms are an important source of chemical compounds which are appropriate for use as therapeutic agents. Among them, Sea pens produce valuable chemical compounds being used as anti-cancer drugs. The aim of this study was to investigate anti-cancer property of extracted and purified compounds from marine organism Sea pen and evaluate their effects on inducing of apoptosis. The extracts were prepared from dried colony of Virgularia gustaviana. The compounds (3β)-Cholest,5en,3ol (cholesterol) (15 mg), Hexadecanoic acid (2.5 mg) and 2-Hexadecanol (10.7 mg) were identified by GC-MS and NMR. The cytotoxic effects of the compounds were evaluated on Hela and MDA-Mb-231 human cancer cell lines with MTT assay. Immunocytochemistry and Western Blot analyses were used to evaluate the expression of apoptosis related markers Caspase 3, Caspase 8, Bax and BCL2 in cancer cells after treating with three compounds. The purified compounds reduced viability of human breast cancer cell line MDA-MB-231 and human cervical cancer cell line Hela concentration-dependently. 2-Hexadecanol reduced significantly the viability of both cancer cell lines in comparison to the other purified compounds. Treatment of cancer cells with the three purified compounds increased the expression of caspase-3, caspase-8 and Bax proteins and decreased the relative Bcl-2/Bax ratio, demonstrating induction of apoptosis as possible mechanism of action. According to the results, three purified compounds inhibit the growth of cancer cells by inducing of apoptosis pathway; an effect which needs to be further investigated in the future studies

Green oxidation of alcohols by using hydrogen peroxide in water in the presence of magnetic Fe₃O₄ nanoparticles as recoverable catalyst

<div><p>Magnetically nano Fe₃O₄ efficiently catalyzes green oxidation of primary and secondary benzylic and aliphatic alcohols to give the corresponding carbonyl products in good yields. The reactions were carried out in an aqueous medium in the presence of hydrogen peroxide as an oxidant at 50°C. In addition, the magnetically nano Fe₃O₄ catalyst could be reused up to four runs without any significant loss of activities. Catalyst was characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, thermogravimetric analysis, vibrating sample magnetometer, and IR.</p></div