Synthesis and assessment of poly(acrylic acid)/polyvinylpyrrolidone interpenetrating network as a matrix for oral mucosa cells

Dual-crosslinked zwitterionic hydrogel: a facile platform of wearable colorimetric urea sensors

Zwitterionic hydrogel based on a dual-crosslinked network of pluronic F-127 dimethacrylate (PLU-DMA) and a terpolymer, poly(sulfobetaine methacrylate)-co-methacrylic acid-co-N-methacryloyloxyethyl tyrosine methylester) (PSBMM) was prepared and successfully applied as an enzyme-based colorimetric sensor of urea on diaper. The prepared hydrogel possessed good mechanical property while preserving its swelling capability. The urease-incorporated hydrogel exhibited a vivid color change from yellow to orange and red, enabling semi-qualitative detection of urea via naked eye in a linear range of 0-0.7 M covering a cut-off value of 0.3 M, which allow for distinguishing between the chronic kidney-prone patients from the normal individuals. The hydrogel was found to be non-toxic and demonstrated effective enzyme preservation by maintaining more than 80% of urease activity up to 14 days. This hydrogel-based urea sensor was also validated by laser desorption ionization mass spectrometry (LDI-MS) with satisfactory results. This platform demonstrated its potential integration on diaper for real-time screening of urea in the point-of-care diagnostics of chronic kidney disease (CKD).

Microbiome-friendly PS/PVP electrospun fibrous membrane with antibiofilm properties for dental engineering

Dental caries is one of the most prevalent and biofilm-associated oral diseases in humans. Streptococcus mutans, with a high ability to form biofilms by adhering to hard surfaces, has been established as an important etiological agent for dental caries. Therefore, it is crucial to find a way to prevent the formation of cariogenic biofilm. Here, we report an electrospun fibrous membrane that could inhibit the adhesion and biofilm formation of S. mutans. Also, the polystyrene (PS)/polyvinyl pyrrolidone (PVP) electrospun fibrous membrane altered the 3D biofilm architecture and decreased water-insoluble extracellular polysaccharide production. Notably, the anti-adhesion mechanism which laid in Coulomb repulsion between the negatively charged PS/PVP electrospun fibrous membrane and S. mutans was detected by zeta potential. Furthermore, metagenomics sequencing analysis and CCK-8 assay indicated that PS/PVP electrospun fibrous membrane was microbiome-friendly and displayed no influence on the cell viability of human gingival epithelial cells and human oral keratinocytes. Moreover, an in vitro simulation experiment demonstrated that PS/PVP electrospun fibrous membrane could decrease colony-forming unit counts of S. mutans effectively, and PS/PVP electrospun fibrous membrane carrying calcium fluoride displayed better anti-adhesion ability than that of PS/PVP electrospun fibrous membrane alone. Collectively, this research showed that the PS/PVP electrospun fibrous membrane has potential applications in controlling and preventing dental caries.

Nanoemulsion carriers of porous γ-alumina modified by polyvinylpyrrolidone and carboxymethyl cellulose for pH-sensitive delivery of 5-fluorouracil

5-Fluorouracil (5-FU) is a cytotoxic drug with a low half-life. These features can cause some problems such as burst drug release and numerous side effects. In the present study, a pH-sensitive nanocomposite of polyvinylpyrrolidone (PVP)/carboxymethyl cellulose (CMC)/γ-alumina developed by using water in oil in water (W/O/W) double emulsion method. The fabricated emulsion has been employed as the 5-FU carrier to investigate its effects on drug half-life, side effects, drug loading efficiency (DLE), and drug entrapment efficiency (DEE). Analyzing the FTIR and XRD indicated the successful loading of 5-FU into the nanocarrier and affirmed the synthesized nanocomposite's chemical bonding and crystalline features. Furthermore, by using DLS and Zeta potential assessment, size and undersize distribution, as well as the stability of the drug-loaded nanocomposite were determined, which demonstrated the monodisperse and stable nanoparticles. Moreover, the nanocomposites with spherical shapes and homogeneous surfaces were shown in FE-SEM, which indicated good compatibility for the constituents of the nanocomposites. Moreover, by employing BET analysis the porosity has been investigated. Drug release pattern was studied, which indicated a controlled drug release behavior with above 96 h drug retention. Besides, the loading and entrapment efficiencies were obtained 44 % and 86 %, respectively. Furthermore, the curve fitting technique has been employed and the predominant release mechanism has been determined to evaluate the best-fitted kinetic models. MTT assay and flow cytometry assessment has been carried out to investigate the cytotoxic effects of the fabricated drug-loaded nanocomposite on MCF-7 and normal cells. The results showed enhanced cytotoxicity and late apoptosis for the PVP/CMC/γ-alumina/5-FU. Based on the MTT assay outcomes on normal cell lines (L929), which indicated above 90 % cell viability, the biocompatibility and biosafety of the synthesized nanocarrier have been confirmed. Moreover, due to the porosity of the PVP/CMC/γ-alumina, this nanocarrier can exploit from high specific surface area and be more sensitive to environmental conditions such as pH. These outcomes propose that the novel pH-sensitive PVP/CMC/γ-alumina nanocomposite can be a potential candidate for drug delivery applications, especially for cancer therapy.

Mucoadhesive carriers for oral drug delivery

Among the various dosage forms, oral medicine has extensive benefits including ease of administration and patients' compliance, over injectable, suppositories, ocular and nasal. Despite of extensive demand and emerging advantages, over 50% of therapeutic molecules are not available in oral form due to their physicochemical properties. More importantly, most of the biologics, proteins, peptide, and large molecular drugs are mostly available in injectable form. Conventional oral drug delivery system has limitation such as degradation and lack of stability within stomach due to presence of highly acidic gastric fluid, hinders their therapeutic efficacy and demand more frequent and higher dosing. Hence, formulation for controlled, sustained, and targeted drug delivery, need to be designed with feasibility to target the specific region of gastrointestinal (GI) tract such as stomach, small intestine, intestine lymphatic, and colon is challenging. Among various oral delivery approaches, mucoadhesive vehicles are promising and has potential for improving oral drug retention and controlled absorption to treat local diseases within the GI tract, as well systemic diseases. This review provides the overview about the challenges and opportunities to design mucoadhesive formulation for oral delivery of therapeutics in a way to target the specific region of the GI tract. Finally, we have concluded with future perspective and potential of mucoadhesive formulations for oral local and systemic delivery.

Lyophilized Polyvinylpyrrolidone Hydrogel for Culture of Human Oral Mucosa Stem Cells

This work shows the synthesis of a polyvinylpyrrolidone (PVP) hydrogel by heat-activated polymerization and explores the production of hydrogels with an open porous network by lyophilisation to allow the three-dimensional culture of human oral mucosa stem cells (hOMSCs). The swollen hydrogel showed a storage modulus similar to oral mucosa and elastic solid rheological behaviour without sol transition. A comprehensive characterization of porosity by scanning electron microscopy, mercury intrusion porosimetry and nano-computed tomography (with spatial resolution below 1 μm) showed that lyophilisation resulted in the heterogeneous incorporation of closed oval-like pores in the hydrogel with broad size distribution (5 to 180 μm, d₅₀ = 65 μm). Human oral mucosa biopsies were used to isolate hOMSCs, expressing typical markers of mesenchymal stem cells in more than 95% of the cell population. Direct contact cytotoxicity assay demonstrated that PVP hydrogel have no negative effect on cell metabolic activity, allowing the culture of hOMSCs with normal fusiform morphology. Pore connectivity should be improved in future to allow cell growth in the bulk of the PVP hydrogel.

Synthesis and characterization of a polymeric network made of polyethylene glycol and chitosan as a treatment with antibacterial properties for skin wounds

Polyethylene glycol has been widely investigated for wound healing and dressing applications. Despite its advantages (i.e. great biocompatibility), polyethylene glycol lacks antibacterial activity. For this reason, semi-interpenetrated polymeric networks were prepared by combining a chemically cross-linked polyethylene glycol network with chitosan. The aim of this work was to identify the best amount of chitosan able to improve the antibacterial properties against Staphylococcus aureus. Briefly, the networks were synthesized by a sequential method, adding chitosan in different proportion to the polyethylene glycol. The antibacterial activity was tested following the MGA 0100 of the Pharmacopeia of the United States of Mexico. Fourier-transform infrared with attenuated total reflection spectroscopy, scanning electron microscopy and swelling behavior PBS at 37° C and room temperature were also performed to characterize the polymeric networks. The results showed that PC-2% was able to inhibit the bacterial growth of Staphylococcus aureus even more than Fosfomycin antibiotic. The networks showed cylindrical pores of different sizes (50-100 µm). The maximum swelling of all the networks was achieved in PBS at 37°C (>315%). Free hemoglobin and hemolysis assays were also evaluated to know the compatibility with erythrocytes. Human dermal fibroblasts were used to evaluate direct cytotoxicity. Therefore, the produced gels exerted interesting antibacterial activity and showed good biocompatibility properties.