Molybdesum selenide-based platelet-rich plasma containing carboxymethyl chitosan/polyvinyl pyrrolidone composite antioxidant hydrogels dressing promotes the wound healing.

Excess free radicals at the wound site can cause an inflammatory response, which is not conducive to wound healing. Hydrogels with antioxidant properties can prevent inflammatory storms by scavenging free radicals from the wound site and inhibiting the release of inflammatory factors. In this study, we prepared the carboxymethyl chitosan (CMCS)/polyvinyl pyrrolidone (PVP)/Molybdenum (IV) Selenide (MoSe2), and platelet-rich plasma (PRP) (CMCS/PVP/MoSe2/PRP) hydrogels for accelerating the repair of wounds. In the hydrogels, the MoSe2 can scavenge various free radicals to reduce oxidative stress at the site of inflammation, endowed the hydrogels with antioxidant properties. Interestingly, growth factors released by PRP assisted the tissue repair by promoting the formation of new capillaries. CMCS as a backbone not only showed good biocompatibility and biodegradability but also played a significant role in maintaining the sustained release of growth factors. In addition, incorporating PVP enhanced the tissue adhesion and mechanical properties. The multifunctional composite antioxidant hydrogels have good swelling properties and biodegradability, which is completely degraded within 28 days. Thus, the antioxidant CMCS/PVP/MoSe2/PRP hydrogels provide a new idea for designing ideal multifunctional wound dressings.

Copper oxide(I) nanoparticle-modified cellulose acetate membranes with enhanced antibacterial and antifouling properties.

Cellulose acetate membranes exhibit a potential to be applied in hemodialysis. However, their performance is limited by membrane fouling and a lack of antibacterial properties. In this research, copper oxide (I) nanoparticles were fabricated in situ into a cellulose acetate matrix in the presence of polyvinylpyrrolidone (pore-forming agent) and sulfobetaine (stabilising agent) to reduce the leakage of copper ions from nano-enhanced membranes. The influence of nanoparticles on the membrane structure and their antibacterial and antifouling properties were investigated. The results showed that incorporating Cu2O NPs imparted significant antibacterial properties against Staphylococcus aureus and fouling resistance under physiological conditions. The Cu2O NPs-modified membrane could pave the way for potential dialysis applications.

Drug-Polymer Nanodroplet Formation and Morphology Drive Solubility Enhancement of GDC-0810.

Nanodroplet formation is important to achieve supersaturation of active pharmaceutical ingredients (APIs) in an amorphous solid dispersion. The aim of the current study was to explore how polymer composition, architecture, molar mass, and surfactant concentration affect polymer-drug nanodroplet morphology with the breast cancer API, GDC-0810. The impact of nanodroplet size and morphology on dissolution efficacy and drug loading capacity was explored using polarized light microscopy, dynamic light scattering, and cryogenic transmission electron microscopy. Poly(N-isopropylacrylamide-stat-N,N-dimethylacrylamide) (PND) was synthesized as two linear derivatives and two bottlebrush derivatives with carboxylated or PEGylated end-groups. Hydroxypropyl methylcellulose acetate succinate grade MF (HPMCAS-MF) and poly(vinylpyrrolidone-co-vinyl acetate) (PVPVA) were included as commercial polymer controls. We report the first copolymerization synthesis of a PVPVA bottlebrush copolymer, which was the highest performing excipient in this study, maintaining 688 µg/mL GDC-0810 concentration at 60 wt % drug loading. This is likely due to strong polymer-drug noncovalent interactions and the compaction of GDC-0810 along the PVPVA bottlebrush backbone. Overall, it was observed that the most effective formulations had a hydrodynamic radius less than 25 nm with tightly compacted nanodroplet morphologies.

Computer-aided optimization of carbidopa/levodopa orally disintegrating tablets.

OBJECTIVE: This study aimed to optimize the formulation of carbidopa/levodopa orally disintegrating tablets (ODTs) in order to improve their disintegration performance, and facilitate easier medication intake for Parkinson's patients. METHOD: The response surface methodology (RSM) was used to optimize the formulation, with the content of cross-linked polyvinylpyrrolidone (PVPP), microcrystalline cellulose (MCC), and mannitol (MNT) as independent variables, and disintegration time as the response parameter. Python was utilized to model Carr Indices and mixing time to determine the suitable mixing time. Direct compression (DC) was used for the preparation of ODTs. RESULT: The optimization process resulted in the following values for the independent variables: 7.04% PVPP, 22.02% MCC, and 16.21% MNT. By optimizing the mixing time using Python, it was reduced to 14.19 min. The ODTs prepared using the optimized formulation and a mixing time of 14.19 min exhibited disintegration times of 16.74 s in vitro and 17.63 s in vivo. The content uniformity of levodopa and carbidopa was found to be 100.83% and 99.48%, respectively. CONCLUSION: The ODTs optimized using RSM and Python demonstrated excellent disintegration performance, leading to a decrease in the time the drug exists in solid form in the oral cavity. This improvement in disintegration time reduced the difficulty of swallowing for patients and enhanced medication compliance, while still ensuring that ODTs prepared by DC had sufficient mechanical strength to meet storage and transportation requirements.

Differentiation of Wharton's Jelly-derived mesenchymal stem cells into insulin-producing beta cells with the enhanced functional level on electrospun PRP-PVP-PCL/PCL fiber scaffold.

Diabetes is a global problem that threatens human health. Cell therapy methods using stem cells, and tissue engineering of pancreatic islets as new therapeutic approaches have increased the chances of successful diabetes treatment. In this study, to differentiate Wharton's Jelly-derived mesenchymal stem cells (WJ-MSCs) into insulin-producing cells (IPCs) with improved maturity, and function, platelet-rich plasma (PRP)-Polyvinylpyrrolidone (PVP)-Polycaprolactone (PCL)/PCL scaffold was designed. The two-dimensional (2D) control group included cell culture without differentiation medium, and the experimental groups included 2D, and three-dimensional (3D) groups with pancreatic beta cell differentiation medium. WJ-MSCs-derived IPCs on PRP-PVP-PCL/PCL scaffold took round cluster morphology, the typical pancreatic islets morphology. Real-time PCR, immunocytochemistry, and flowcytometry data showed a significant increase in pancreatic marker genes in WJ-MSCs-derived IPCs on the PRP-PVP-PCL/PCL scaffold compared to the 2D-experimental group. Also, using the ELISA assay, a significant increase in the secretion of insulin, and C-peptide was measured in the WJ-MSCs-derived IPCs of the 3D-experimental group compared to the 2D experimental group, the highest amount of insulin (38 µlU/ml), and C-peptide (43 pmol/l) secretion was in the 3D experimental group, and in response to 25 mM glucose solution, which indicated a significant improvement in the functional level of the WJ-MSCs-derived IPCs in the 3D group. The results showed that the PRP-PVP-PCL/PCL scaffold can provide an appropriate microenvironment for the engineering of pancreatic islets, and the generation of IPCs.

Development and characterization of films from Campomanesia xanthocarpa and commercial citrus pectins with different degrees of methyl-esterification.

In this study, pectins from commercial citrus and isolated from gabiroba (Campomanesia xanthocarpa) fruits, were obtained with different degrees of methyl-esterification (DM) and applied in the films. The DM ranged from 0 % to 62.5 % and the gradual de-esterification process was confirmed by mono-dimensional analysis (1H NMR). In order to investigate the influence of DM values in pectin film properties, PCP (DM: 62.5 %); PCP-5 (DM: 37.4 %); PCP-15 (DM: 19.1 %), and a fully de-esterified sample PCP-35 (DM: 0 %) were selected. The functional properties of the films clearly showed that the DM and cross-linking process are necessary to obtain a material with water resistance. Furthermore, pectin isolated from the fruits of gabiroba was purified (GW-Na, DM: 51.9 %) and partially de-esterified (GW-Na-5, DM: 37.1 %). These pectins were used, for the first time, in development of films and the physical and mechanical properties were compared with films made with PCP and PCP-5 samples. GW-Na and GW-Na-5 films presented suitable properties, with reduced solubility reduced (57.1 and 26.2 %), high degree of swelling (2.14 and 2.26), low flexibility (18.05 and 6.11 MPa), respectively. High strength and rigidity (99.36 and 1040.9 MPa), for both films (GW-Na and GW-Na-5) were demonstrated, similar to that obtained by analyzed citrus pectin.

Hybrid (Bovine Serum Albumin)/Poly(N-vinyl-2-pyrrolidone-co-acrylic acid)-Shelled Microbubbles as Advanced Ultrasound Contrast Agents.

Microbubbles are routinely used ultrasound contrast agents in the clinic. While a soft protein shell is commercially preferable for imaging purposes, a rigid polymer shell demonstrates prolonged agent stability. Hence, combining polymers and proteins in one shell composition can advance microbubble properties. We formulated the hybrid "protein-copolymer" microbubble shell with a complex of bovine serum albumin and an amphiphilic copolymer of N-vinyl-2-pyrrolidone and acrylic acid. The resulting microbubbles demonstrated advanced physicochemical and acoustic properties, preserving in vitro biocompatibility. Adjusting the mass ratio between protein and copolymer allowed fine tuning of the microbubble properties of concentration (by two orders, up to 1010 MBs/mL), mean size (from 0.8 to 5 µm), and shell thickness (from 28 to 50 nm). In addition, the minimum air-liquid surface tension for the "protein-copolymer" solution enabled the highest bubble concentration. At the same time, a higher copolymer amount in the bubble shell increased the bubble size and tuned duration and intensity of the contrast during an ultrasound procedure. Demonstrated results exemplify the potential of the hybrid "protein-polymer" microbubble shell, allowing tailoring of microbubble properties for image-guided applications, combining advances of each material involved in the formulation.

Comprehensive Insight into Chemical Stability of Important Antidiabetic Drug Vildagliptin Using Chromatography (LC-UV and UHPLC-DAD-MS) and Spectroscopy (Mid-IR and NIR with PCA).

During forced degradation, the intrinsic stability of active pharmaceutical ingredients (APIs) could be determined and possible impurities that would occur during the shelf life of the drug substance or the drug product could be estimated. Vildagliptin belongs to relatively new oral antidiabetic drugs named gliptins, inhibiting dipeptidyl peptidase 4 (DPP-4) and prolonging the activities of the endogenous incretin hormones. At the same time, some gliptins were shown as prone to degradation under specific pH and temperature conditions, as well as in the presence of some reactive excipients. Thus, forced degradation of vildagliptin was performed at high temperature in extreme pH and oxidative conditions. Then, selective LC-UV was used for quantitative determination of non-degraded vildagliptin in the presence of its degradation products and for degradation kinetics. Finally, identification of degradation products of vildagliptin was performed using an UHPLC-DAD-MS with positive ESI. Stability of vildagliptin was also examined in the presence of pharmaceutical excipients, using mid-IR and NIR with principal component analysis (PCA). At 70 °C almost complete disintegration of vildagliptin occurred in acidic, basic, and oxidative media. What is more, high degradation of vildagliptin following the pseudo first-order kinetics was observed at room temperature with calculated k values 4.76 × 10-4 s-1, 3.11 × 10-4 s-1, and 1.73 × 10-4 s-1 for oxidative, basic and acidic conditions, respectively. Next, new degradation products of vildagliptin were detected using UHPLC-DAD-MS and their molecular structures were proposed. Three degradants were formed under basic and acidic conditions, and were identified as [(3-hydroxytricyclo- [3.3.1.13,7]decan-1-yl)amino]acetic acid, 1-{[(3-hydroxytricyclo[3.3.1.13,7]decan-1-yl)amino]acetyl}-pyrrolidine-2-carboxylic acid and its O-methyl ester. The fourth degradant was formed in basic, acidic, and oxidative conditions, and was identified as 1-{[(3-hydroxytricyclo[3.3.1.13,7]-decan-1-yl)amino]acetyl}pyrrolidine-2-carboxamide. When stability of vildagliptin was examined in the presence of four excipients under high temperature and humidity, a visible impact of lactose, mannitol, magnesium stearate, and polyvinylpirrolidone was observed, affecting-NH- and CO groups of the drug. The obtained results (kinetic parameters, interactions with excipients) may serve pharmaceutical industry to prevent chemical changes in final pharmaceutical products containing vildagliptin. Other results (e.g., identification of new degradation products) may serve as a starting point for qualifying new degradants of vildagliptin as it is related to substances in pharmacopoeias.

Combination of polyvinylpolypyrrolidone extraction and standard addition strategy for the accurate determination of multiple allergen residues in red wine by UPLC-MS/MS.

During the winemaking process, fining materials derived from milk and egg products are traditionally used to remove undesirable substances to reduce bitterness and astringency. The possible residues of allergens in treated wine may pose a potential risk for allergy patients. In this study, we developed a method for the simultaneous quantification of eight allergens (αS1-casein, αS2-casein, ß-casein, κ-casein, ß-lactoglobulin, lysozyme, ovalbumin and ovotransferrin) in red wine by ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The sample was extracted with polyvinylpolypyrrolidone (PVPP) solution, following trypsin digestion and peptide-level purification by solid-phase extraction (SPE). A strategy based on standard addition was used for the accurate quantification of the target allergens in wine products. The limits of detection (LODs) were shown to be 0.003-0.015 µg/mL for milk allergens and 0.1 µg/mL for egg allergens. This economical and reliable method would be appropriate for routine analysis and further allergen label management for red wine.

Synthesis and characterization of chitosan/polyvinylpyrrolidone coated nanoporous γ-Alumina as a pH-sensitive carrier for controlled release of quercetin.

pH-sensitive drug delivery systems based on amphiphilic copolymers constitute a promising strategy to overcome some challenges to cancer treatment. In the present study, quercetin-loaded chitosan/polyvinylpyrrolidone/γ-Alumina nanocomposite was fabricated through a double oil in water emulsification method for the first time. γ-Alumina was incorporated to improve the drug loading efficiency and release behavior of polyvinylpyrrolidone and chitosan copolymeric hydrogel. γ-Alumina nanoparticles were obtained by the sol-gel method with a nanoporous structure, high surface area, and hydroxyl-rich surface. Quercetin, a natural anticancer agent, was loaded into the nanocomposite as a drug model. XRD and FTIR analyses confirmed the crystalline properties and chemical bonding of the prepared nanocomposite. The size of drug-loaded nanocomposites was 141 nm with monodisperse particle distribution, having a spherical shape approved by DLS analysis and FE-SEM, respectively. Incorporating γ-Alumina nanoparticles improved the encapsulation efficiency up to 95%. Besides, swelling study and the quercetin release profile demonstrated that γ-Alumina ameliorated pH sensitivity of nanocomposite and a targeted controlled release was obtained. Various release kinetic models were applied to the experimental release data to study the mechanism of drug release. Through MTT assay and flow cytometry, the quercetin-loaded nanocomposite showed significant cytotoxicity on MCF-7 breast cancer cells. Also, the enhanced apoptotic cell death confirmed the anticancer activity of γ-Alumina. These results suggest that the chitosan/polyvinylpyrrolidone/γ-Alumina nanocomposite is a novel pH-sensitive drug delivery system for anticancer applications.

Development of Apremilast Solid Dispersion Using TPGS and PVPVA with Enhanced Solubility and Bioavailability.

Apremilast (APST) is an effective inhibitor of phosphodieasterase 4 (PDE4) which is the first oral drug for the treatment of adult patients with active psoriatic arthritis. However, Apremilast's low solubility restricts its dissolution and bioavailability. In this study, APST solid dispersion with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and Poly(1-vinylpyrrolidone-co-vinyl acetate) (PVPVA) was developed to improve the dissolution and bioavailability of APST by spray drying. A series of TPGS were synthesized to elucidate the effect of the ratio of monoester to diester on solubilizing capacity. X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and Fourier transform infrared spectrophotometry (FT-IR) were used to characterize the solid dispersion, and the results showed that APST was amorphous in solid dispersion. In vitro dissolution study showed that the dissolution rate of solid dispersion in phosphate buffered saline (pH 6.8) was remarkably increased, reaching a release of 90% within 10 min. Moreover, in vivo pharmacokinetics study revealed that the bioavailability of solid dispersion in rats had significant improvement. In particular, its Cmax and AUClast were nearly 22- and 12.9-fold greater as compared to APST form B, respectively. In conclusion, APST solid dispersion with TPGS and PVPVA is an alternative drug delivery system to improve the solubility and oral bioavailability of APST.

Effect of Temperature and Additives on the Interaction of Ciprofloxacin Hydrochloride Drug with Polyvinylpyrrolidone and Bovine Serum Albumin: Spectroscopic and Molecular Docking Study.

The fluoroquinolone antibiotic drug namely ciprofloxacin hydrochloride (CFH) is widely prescribed for the treatment of different bacterial infections. The interaction of CFH with a synthetic polymer, polyvinyl pyrrolidone (PVP), and biopolymer, bovine serum albumin (BSA) was studied by UVvisible and fluorescence spectroscopic methods at different temperatures. The binding constant (K b ) for the CFH-PVP complex was determined from the Benesi-Hildebrand plot. PVP of different molecular weights (MW) (such as 24,000, 40,000, 360,000, and 700,000 g. mole-1) were used for the interaction between CFH and PVP. The gradual increase in K b value and the complexation reaction was found to be much enhanced with the augmentation of the MW of PVP. The values of K b were also found to be increased with increasing temperatures as well as with the increase of electrolyte/acetic acid concentration. The Gibbs free energy of binding (∆G 0) values of the interaction process was negative which indicates the complex formation is thermodynamically spontaneous. The positive values of enthalpy (∆H 0) and entropy (∆S 0) of binding connote that the binding force for CFH-PVP complexation is hydrophobic in nature and the complexation is entropy controlled. The negative intrinsic enthalpy (∆H *,0) values indicate the high stability of CFH-PVP complexes. Molecular docking calculation discloses the existence of similar binding forces between CFH and PVP obtained by the analysis of experimental data from UV-visible spectroscopic method. The binding constant between CFH and BSA (K b ), quenching constant (K sv ), the number of binding sites (n), and the quenching rate constant (K q ) for the CFH-BSA system were also calculated. The values of K sv , K q , and n for the CFH-BSA system are lower in 0.05 mol L-1 urea solution and higher in PVP solutions compared to those of aqueous medium.

Development and characterization of lyophilized cefpodoxime proxetil-Pluronic® F127/polyvinylpyrrolidone K30 solid dispersions with improved dissolution and enhanced antibacterial activity.

The aim of this study was the development of hard-cellulose capsules containing cefpodoxime proxetil (CEF) (BCS Class II) loaded novel Pluronic® F127 (P127)/Polyvinylpyrrolidone K30 (PVP) solid dispersions (SDs) using ultrasonic probe induced solvent-lyophilization method for effective antibacterial treatment by means of improved saturated aqueous solubility, dissolution rate, reduced particle size, and wettability. SDs were evaluated for physical and solid-state analyses. The solubility of pure CEF was calculated as 0.269 ± 0.005 mg/mL, SDs formulated with P127/PVP exhibited increased solubility from 3.5- to 8-fold. Molecular distribution of CEF in SDs and formation of CEF loaded amorphous polymeric network were confirmed with morphological study, thermal analysis, Fourier-transform infrared spectroscopy (FT-IR), and 1H-NMR studies. Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), and Klebsiella pneumoniae (ATCC 700603) were used to investigate the antibacterial effectiveness of the SDs. The minimum inhibitory concentration (MIC) values of the P127/PVP SDs were found 2-8 times lower than the pure CEF. All SDs from hard-cellulose capsules exhibited significantly faster release than unprocessed CEF. The profiles of SDs and reference were detected to be dissimilar according to difference (f1) and similarity factor (f2). Hard-cellulose capsules containing CEF loaded P127/PVP SDs appear to be feasible alternative to commercially available CEF tablets for effective antibacterial therapy at lowest dose.

Oenothein B in Eucalyptus Leaf Extract Suppresses Fructose Absorption in Caco-2 Cells.

Inhibition of fructose absorption may suppress adiposity and adiposity-related diseases caused by fructose ingestion. Eucalyptus leaf extract (ELE) inhibits intestinal fructose absorption (but not glucose absorption); however, its active compound has not yet been identified. Therefore, we evaluated the inhibitory activity of ELE obtained from Eucalyptus globulus using an intestinal fructose permeation assay with the human intestinal epithelial cell line Caco-2. The luminal sides of a cell monolayer model cultured on membrane filters were exposed to fructose with or without the ELE. Cellular fructose permeation was evaluated by measuring the fructose concentration in the medium on the basolateral side. ELE inhibited 65% of fructose absorption at a final concentration of 1 mg/mL. Oenothein B isolated from the ELE strongly inhibited fructose absorption; the inhibition rate was 63% at a final concentration of 5 µg/mL. Oenothein B did not affect glucose absorption. In contrast, the other major constituents (i.e., gallic acid and ellagic acid) showed little fructose-inhibitory activity. To our knowledge, this is the first report that oenothein B in ELE strongly inhibits fructose absorption in vitro. ELE containing oenothein B can prevent and ameliorate obesity and other diseases caused by dietary fructose consumption.

The microneedles carrying cisplatin and IR820 to perform synergistic chemo-photodynamic therapy against breast cancer.

BACKGROUNDS: Surgical resection and adjunct chemotherapy or radio-therapy has been applied for the therapy of superficial malignant tumor in clinics. Whereas, there are still some problems limit its clinical use, such as severe pains and side effect. Thus, it is urgent need to develop effective, minimally invasive and low toxicity therapy stagey for superficial malignant tumor. Topical drug administration such as microneedle patches shows the advantages of reduced systemic toxicity and nimble application and, as a result, a great potential to treat superficial tumors. METHODS: In this study, microneedle (MN) patches were fabricated to deliver photosensitizer IR820 and chemotherapy agent cisplatin (CDDP) for synergistic chemo-photodynamic therapy against breast cancer. RESULTS: The MN could be completely inserted into the skin and the compounds carrying tips could be embedded within the target issue for locoregional cancer treatment. The photodynamic therapeutic effects can be precisely controlled and switched on and off on demand simply by adjusting laser. The used base material vinylpyrrolidone-vinyl acetate copolymer (PVPVA) is soluble in both ethanol and water, facilitating the load of both water-soluble and water-insoluble drugs. CONCLUSIONS: Thus, the developed MN patch offers an effective, user-friendly, controllable and low-toxicity option for patients requiring long-term and repeated cancer treatments.

Hot melt extrusion paired fused deposition modeling 3D printing to develop hydroxypropyl cellulose based floating tablets of cinnarizine.

Three-dimensional printing could serve as a platform to fabricate individualized medicines and complex-structured solid dosage forms. Herein, hot melt extrusion was coupled with 3D printing to develop a unique gastro retentive dosage form to personalize treatment of cinnarizine or other narrow absorption window drugs. The mechanical strength of the extruded strands was optimized for printing by combining two polymers, hydroxypropyl cellulose and vinylpyrrolidone vinyl acetate copolymer. The unit dose, floating force, and release profile were controlled by the printing parameters and object design. The tablets floated immediately within the FaSSGF, and floating force was relatively constant up to 12 h. Drug release followed zero-order kinetics and could be controlled from 6 h to ≥ 12 h. Input variables had a good correlation (R > 0.95) with unit dose, floating force, and dissolution profile (p < 0.05). Authors successfully proposed and tested a new paradigm of individualized medicine fabrication to meet individual patient needs.

Adding value to polyvinylpolypyrrolidone winery residue: A resource of polyphenols with neuroprotective effects and ability to modulate type 2 diabetes-relevant enzymes.

A polyphenols-rich extract was obtained from polyvinylpolypyrrolidone (PVPP) winery residue, and its neuroprotective effects and ability to modulate the kinetics of type 2 diabetes-relevant enzymes were characterized. The PVPP-white wine extract is a mixture of polyphenols (840.08 ± 161.25 µg/mg, dry weight) dominated by proanthocyanidins and hydroxycinnamic acids, affording strong antioxidant activity, as detected by the protection of membrane lipids against oxidation and superoxide radical anion scavenging activity. Regarding type 2 diabetes framework, the extract inhibits α-glucosidase (Ki = 166.9 µg/mL) and aldose reductase (Ki = 127.5 µg/mL) through non-competitive mechanisms. Despite the modest ability to inhibit rat brain acetylcholinesterase, it protects neuronal SH-SY5Y cells against oxidative damage promoted by glutamate, decreasing reactive oxygen species generation and preserving cell redox state. Thus, PVPP-white wine extract has potential to support the development of functional foods and/or nutraceuticals aiming neuroprotection and glucose homeostasis regulation, with high relevance in Alzheimers disease and type 2 diabetes interlink.

Mechanodegradation of Polymers: A Limiting Factor of Mechanochemical Activation in the Production of Amorphous Solid Dispersions by Cryomilling.

In this study, we report on the influence of mechanochemical activation on the chemical stability of amorphous solid dispersions made up of indomethacin and hydroxypropyl methyl cellulose (HPMC), poly(vinylpyrrolidone) (PVP), poly(vinylpyrrolidone vinylacetate) (PVPVA), or Soluplus. In agreement with our recently published work, all applied carriers were found to be prone to polymer degradation. Covalent bonds within the polymers were cleaved and mechanoradicals were generated. Furthermore, decomposition of indomethacin was also observed but occurred only in the presence of polymers. Hence, it is proposed that the generated mechanoradicals from the polymers are responsible for the chemical degradation of indomethacin. Our study also strongly suggests the existence of a critical polymer- and process-dependent molecular weight limit "M∞", below which only limited mechanodegradation takes place since the lower-molecular-weight polymer PVP K12PF had a less profound influence on the degradation of indomethacin in comparison to PVP K25.

Synthesis of Co3S4-SnO2/polyvinylpyrrolidone-cellulose heterojunction as highly performance catalyst for photocatalytic and antimicrobial properties under ultra-violet irradiation.

In this work, we present Co3S4-SnO2 supported polyvinylpyrrolidone-cellulose (PVPCS) nano-structure for Lidocaine degradation. The nanostructure was characterized by various techniques i.e. morphological and optical ones. The results have demonstrated that Co3S4-SnO2 nanocomposites were evenly supported on the PVPCS. Moreover, the photocatalysis performances of the catalysts were investigated under ultra-violet (UV) light irradiation. The nano-structure Co3S4-SnO2/PVPCS composite (98.72%) revealed the highest photocatalysis performance as compared to SnO2 nanoparticles, and Co3S4-SnO2 nanocomposites. The photo-stability of nano-structure Co3S4-SnO2/PVPCS composite was characterized using cyclic catalytic experimental. Results demonstrated a substantially stable performance of the nano-structure Co3S4-SnO2/PVPCS composite. The biological properties of Co3S4-SnO2/PVPCS composite were investigated through the antibacterial (versus Staphylococcus aureus, and Escherichia coli) and antifungal studies (Candida albicans). As the results declared, Co3S4-SnO2 nanocomposites have substantial biological properties as compared to SnO2 nanoparticles, and Co3S4-SnO2 nanocomposites.

Biomimetic sensors targeting oxidized-low-density lipoprotein with molecularly imprinted polymers.

Oxidized-low-density lipoprotein (oxLDL) is well-recognized as an actual patho-atherogenic lipoprotein: elevated serum concentration of oxLDL increases the risk for developing atherosclerosis, leading to coronary artery disease (CAD). Herein, we report an approach for sensing oxLDL directly in serum with molecularly imprinted polymer (MIP) thin films on quartz crystal microbalance (QCM). The resulting MIP sensors show low cross-reaction toward low-density lipoprotein (LDL) and high-density lipoprotein (HDL): signals are around one magnitude smaller. Very-low-density lipoprotein (VLDL) and human serum albumin (HSA) do not lead to any significant sensor response. The sensor allowed for accurately assessing oxLDL over the detection range of 86-5600 µg dL-1, which covers the clinically relevant concentrations. The sensor determines oxLDL with recovery accuracy of 92-107% and a precision of 1-8% coefficient variation. Compared with commercially available oxLDL ELISA test kit our sensor reveals similar characteristics obtaining a correlation coefficient of 0.98. However, the sensors have rapid response times of 10 min compared to 210 min of ELISA, which demonstrates their efficiency in assessing this sensitive atherogenic biomarker for CAD diagnostics.