Poly (hydroxyethyl methacrylate-glycidyl methacrylate) films modified with different functional groups: In vitro interactions with platelets and rat stem cells

Dynamic modulation and epoxy functionalization of protein-mediated enoate ester-based hybrid cryogels

The current work is focused on the preparation of protein-mediated poly(hydroxyethyl methacrylate-co-glycidyl methacrylate) copolymer as a self-template for in situ synthesis of hybrid gels. Gelatin, collagen, biotin, and l-arginine were used to create hybrid materials with adjustable swelling and elastic properties. Hybrid cryogels tended to swell more than hybrid hydrogels due to their porous nature. Collaged-doped cryogels had the highest swelling, whereas gelatin-doped hybrids showed enhanced elastic modulus. All hybrid gels exhibited pH-sensitive swelling to controlled release applications depending on the degree of protonation of NH₂ and COOH groups in the side chains. At low pH conditions, hybrid cryogels exhibited a higher swelling tendency compared to hydrogels. Ion-stimulus-response of hybrid gels was studied to evaluate the effect of salt concentration and features of ambient ions on swelling. Depending on the polyelectrolytic or polyampholytic nature, the extent of swelling in NaCl and KCl solutions varied according to the charge distribution in the network chains. Hybrid gels showed excellent adsorption performance for methyl orange by the presence of epoxy, hydroxyl groups, amino and carboxyl groups providing sufficient active sites. Adsorption capacity of hybrid cryogels is higher than that of hydrogels. The removal rate 97/%, reached an equilibrium state in a short period, suggested that collagen-doped hybrid cryogels have a potential application to remove dyestuff from wastewater. In relation to the decrease of methyl orange concentration in solution, adsorption process followed pseudo-second-order kinetic model. Avrami model has provided a better experimental-calculated fit and adsorption thermodynamics analysis indicated that the adsorption was a spontaneous process with a negative standard free energy. The characteristic findings from this research will provide insights into the design and application of enoate-ester and protein-based combinations in the food, biomedical and cosmetic fields.

Fabrication and characterization of PHEMA–gelatin scaffold enriched with graphene oxide for bone tissue engineering

Background

Growing investigations demonstrate that graphene oxide (GO) has an undeniable impact on repairing damaged bone tissue. Moreover, it has been stated in the literatures that poly(2-hydroxyethyl methacrylate) (PHEMA) and gelatin could provide a biocompatible structure.

Methods

In this research, we fabricated a scaffold using freeze-drying method comprised of PHEMA and gelatin, combined with GO. The validation of the successful fabrication of the scaffolds was performed utilizing Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction assay (XRD). The microstructure of the scaffolds was observed using scanning electron microscopy (SEM). The structural properties of the scaffolds including mechanical strength, hydrophilicity, electrical conductivity, and degradation rate were also evaluated. Human bone marrow‐derived mesenchymal stem cells (hBM-MSCs) were used to evaluate the cytotoxicity of the prepared scaffolds. The osteogenic potential of the GO-containing scaffolds was studied by measuring the alkaline phosphatase (ALP) activity after 7, 14, and 21 days cell culturing.

Results

SEM assay showed a porous interconnected scaffold with approximate pore size of 50–300 μm, appropriate for bone regeneration. The increase in GO concentration from 0.25 to 0.75% w/v exhibited a significant improvement in scaffolds compressive modulus from 9.03 ± 0.36 to 42.82 ± 1.63 MPa. Conventional four-probe analysis confirmed the electrical conductivity of the scaffolds in the semiconductor range. The degradation rate of the samples appeared to be in compliance with bone healing process. The scaffolds exhibited no cytotoxicity using MTT assay against hBM-MSCs. ALP analysis indicated that the PHEMA–Gel–GO scaffolds could efficiently cause the differentiation of hBM-MSCs into osteoblasts after 21 days, even without the addition of the osteogenic differentiation medium.

Conclusion

Based on the results of this research, it can be stated that the PHEMA–Gel–GO composition is a promising platform for bone tissue engineering.

Polymer-Coated NH2-UiO-66 for the Codelivery of DOX/pCRISPR

Herein, the NH₂-UiO-66 metal organic framework (MOF) has been green synthesized with the assistance of high gravity to provide a suitable and safe platform for drug loading. The NH₂-UiO-66 MOF was characterized using a field-emission scanning electron microscope, transmission electron microscope (TEM), X-ray diffraction, and zeta potential analysis. Doxorubicin was then encapsulated physically on the porosity of the green MOF. Two different stimulus polymers, p(HEMA) and p(NIPAM), were used as the coating agents of the MOFs. Doxorubicin was loaded onto the polymer-coated MOFs as well, and a drug payload of more than 51% was obtained, which is a record by itself. In the next step, pCRISPR was successfully tagged on the surface of the modified MOFs, and the performance of the final nanosystems were evaluated by the GFP expression. In addition, successful loadings and internalizations of doxorubicin were investigated via confocal laser scanning microscopy. Cellular images from the HeLa cell line for the UiO-66@DOX@pCRISPR and GMA-UiO-66@DOX@pCRISPR do not show any promising and successful gene transfections, with a maximum EGFP of 1.6%; however, the results for the p(HEMA)-GMA-UiO-66@DOX@pCRISPR show up to 4.3% transfection efficiency. Also, the results for the p(NIPAM)-GMA-UiO-66@DOX@pCRISPR showed up to 6.4% transfection efficiency, which is the first and superior report of a MOF-based nanocarrier for the delivery of pCRISPR. Furthermore, the MTT assay does not shown any critical cytotoxicity, which is a promising result for further biomedical applications. At the end of the study, the morphologies of all of the nanomaterials were screened after drug and gene delivery procedures and showed partial degradation of the nanomaterial. However, the cubic structure of the MOFs has been shown in TEM, and this is further proof of the stability of these green MOFs for biomedical applications.

Electrospun GelMA fibers and p(HEMA) matrix composite for corneal tissue engineering

The development of biocompatible and transparent three-dimensional materials is desirable for corneal tissue engineering. Inspired from the cornea structure, gelatin methacryloyl-poly(2-hydroxymethyl methacrylate) (GelMA-p(HEMA)) composite hydrogel was fabricated. GelMA fibers were produced via electrospinning and covered with a thin layer of p(HEMA) in the presence of N,N'-methylenebisacrylamide (MBA) as cross-linker by drop-casting. The structure of resulting GelMA-p(HEMA) composite was characterized by spectrophotometry, microscopy, and swelling studies. Biocompatibility and biological properties of the both p(HEMA) and GelMA-p(HEMA) composite have been investigated by 3D cell culture, red blood cell hemolysis, and protein adsorption studies (i.e., human serum albumin, human immunoglobulin and egg white lysozyme). The optical transmittance of the GelMA-p(HEMA) composite was found to be approximately 70% at 550 nm. The GelMA-p(HEMA) composite was biocompatible with tear fluid proteins and convenient for cell adhesion and growth. Thus, as prepared hydrogel composite may find extensive applications in future for the development of corneal tissue engineering as well as preparation of stroma of the corneal material.

Rapid and label-free detection of Brucella melitensis in milk and milk products using an aptasensor

In this work, a novel quartz crystal microbalance (QCM) aptasensor is designed for the diagnosis of Brucella melitensis bacteria, which affects the Mediterranean fever (brucellosis) from the zoonotic diseases that are very common in the Middle East Countries. The method is based on the selection of B. melitensis bacterium from solutions using B. melitensis specific binding aptamer (Apt) attached magnetic nanoparticles. The surface of the magnetic nanoparticles (i.e.,Fe₃O₄) was modified by 3-aminopropyltriethoxysilane (APTES) and then grafted with a hydrophilic macromonomer poly(ethyleneglycol)-methacrylate (PEG-MA) as a first block polymer and glycidylmethacrylate (GMA) as a second block functional polymer via atom transfer radical polymerization (ATRP) method [Fe₃O₄ @SiO₂ @p(PEG-MA-GMA)], then, the specific binding aptamer was immobilized. The aptamer immobilized magnetic nanoparticles were used for the pre-concentration of the target bacterium, and the same aptamer sequence was also immobilized on the QCM chip and used for the quantitative detection of B. melitensis using QCM aptasensor. The detection limits of the QCM aptasensor were in the range 1.0²-1.0⁷ CFU mL^-1, with recoveries up to 79%. The synthesized [Fe₃O₄ @SiO₂ @p(PEGMA-GMA)] nanoparticles showed a good permanence and high isolation recoveries for the pull down of the target bacterium from food samples, after recycling eight times. The method was successfully applied to target bacterium determinations in milk and milk product samples.

Optimizing the release process and modelling of in vitro release data of cis-dichlorodiamminoplatinum (II) encapsulated into poly(2-hydroxyethyl methacrylate) nanocarriers

Drug encapsulated nanocarriers are vehicles to transport the drug molecules and release them at the immediate vicinity of the diseased sites. The aim of this study was to design poly (2-hydroxyethyl methacrylate) nanoparticles (PHEMANPs) as a swelling and diffusion controlled drug release system for achieving sustained release of (cis-dichlorodiamminoplatinum II) CDDP. The study undertakes designing and characterization of nanocarriers, optimization of drug encapsulation, and investigating release dynamics of the CDDP drug. PHEMANPs were prepared by suspension polymerization method followed by post loading of the CDDP onto the nanocarriers. The physicochemical and biopharmaceutical properties were evaluated by FTIR, TEM, FESEM, EDX, DLS, surface charge, water intake studies, in vitro cytotoxicity, protein adsorption and percent haemolysis. Chemical stability of the drug was assessed and in vitro release experiments were performed to optimize formulation by UV spectral analysis. The obtained cumulative release data were fitted to zero, first and Korsmeyer-Peppas kinetic models to gain insights into release kinetics and prevailing drug transport mechanisms. The successful encapsulation of CDDP was achieved in different PHEMANP formulations with maximum drug encapsulation efficiency of approx. 60% and the release kinetics was found to follow the Korsmeyer-Peppas model having non-Fickian mechanism. The results indicated that the CDDP can be formulated with a high payload of PHEMANPs which can serve as promising nanomedicine and help in achieving sustained delivery of drug for targeting tumour.