Electrospinning is a simple, versatile technique for fabricating fibrous nanomaterials with the desirable features of extremely high porosities and large surface areas. Using emulsion electrospinning, polytetrafluoroethylene/polyethene oxide (PTFE/PEO) membranes were fabricated, followed by a sintering process to obtain pure PTFE fibrous membranes, which were further utilized against a polyamide 6 (PA6) membrane for vertical contact-mode triboelectric nanogenerators (TENGs). Electrostatic force microscopy (EFM) measurements of the sintered electrospun PTFE membranes revealed the presence of both positive and negative surface charges owing to the transfer of positive charge from PEO which was further corroborated by FTIR measurements. To enhance the ensuing triboelectric surface charge, a facile negative charge-injection process was carried out onto the electrospun (ES) PTFE subsequently. The fabricated TENG gave a stabilized peak-to-peak open-circuit voltage (Voc) of up to ∼900 V, a short-circuit current density (Jsc) of ∼20 mA m-2, and a corresponding charge density of ∼149 μC m-2, which are ∼12, 14, and 11 times higher than the corresponding values prior to the ion-injection treatment. This increase in the surface charge density is caused by the inversion of positive surface charges with the simultaneous increase in the negative surface charge on the PTFE surface, which was confirmed by using EFM measurements. The negative charge injection led to an enhanced power output density of ∼9 W m-2 with high stability as confirmed from the continuous operation of the ion-injected PTFE/PA6 TENG for 30 000 operation cycles, without any significant reduction in the output. The work thus introduces a relatively simple, cost-effective, and environmentally friendly technique for fabricating fibrous fluoropolymer polymer membranes with high thermal/chemical resistance in TENG field and a direct ion-injection method which is able to dramatically improve the surface negative charge density of the PTFE fibrous membranes.

Recent advancements in the synthesis, properties, and applications of chitosan as the second after cellulose available biopolymer in nature were discussed in this review. A general overview of processing and production procedures from A to Z was highlighted. Chitosan exists in three polymorphic forms which differ in degree of crystallinity (α, β, and γ). Thus, the degree of deacetylation, crystallinity, surface area, and molecular mass significantly affect most applications. Otherwise, the synthesis of chitosan nanofibers is suffering from many drawbacks that were recently treated by co-electrospun with other polymers such as polyvinyl alcohol (PVA), polyethylene oxide (PEO), and polycaprolactone (PCL). Ultimately, this review focuses on the area of new trend utilization of chitosan nanoparticles as nanospheres and nanocapsules, in cartilage and bone regenerative medicine. Owing to its biocompatibility, bioavailability, biodegradability, and costless synthesis, chitosan is a promising biopolymeric structure for water remediation, drug delivery, antimicrobials, and tissue engineering.

Keywords: Bioprinting; Chitosan; Chitosan nanofibers; Chitosan physicochemical properties; Chitosan production; The degree of deacetylation.

To improve therapeutic effects and compatibility of patients, controlled release tablet systems based on polymers are of great interest for pharmaceutical technologies. Poly(ethylene oxide) (PEO) is a non-ionic linear hydrophilic and uncrosslinked polymer available in a number of molecular weights. It is synthesized by ethylene oxide and has many desirable properties for drug delivery applications. This review article aims to summary the recent developments on physicochemical properties of PEO and focus on the recent efforts and developments on PEO as oral controlled release matrix tablets, bioadhesive hydrophilic matrices and osmotic pump tablets. Commercial products employed PEO were also discussed.

A catalytic bioscavenger with broad substrate specificity for the therapeutic and prophylactic defense against recognized chemical threat agents has been a long standing objective of civilian and military research. A catalytic bioscavenger utilizing the bacterial enzyme organophosphorus hydrolase (OPH) is characterized in these studies, and has potential application for both military and civilian personnel in threat scenarios involving either nerve agents or OP pesticides. The present study examines the effects of PEGylation on the biochemical and pharmacological characteristics of OPH. The enzyme was conjugated with linear and branched methyl-PEO(n)-NHS esters of relatively small molecular mass from 333 to 2420Da. PEGylated OPH displayed a decreased maximal catalytic rate, though substantial activity was maintained against two tested substrates: up to 30% with paraoxon and up to 50-60% with demeton-S. The thermostability of the PEGylated enzymes ranged between 60 and 64 degrees C, compared to the unmodified OPH, which is approximately 67 degrees C. The enzyme conjugates revealed a significant improvement of pharmacokinetic properties in animal studies. The clearance from a guinea pig's blood stream significantly decreased relative to unmodified OPH, resulting in an increase of residence time and systemic availability. Evaluation of the humoral immune response indicated that the branched PEG-OPH conjugate significantly reduced production of anti-OPH antibodies, compared to the unmodified enzyme. The OPH-PEG conjugates with improved pharmacokinetic and immunogenicity properties, considerable catalytic activity and thermal stability provide a new opportunity for the in vivo detoxification of the neurotoxic OP compounds.

A poly (lactide-co-glycolide) (PLGA) scaffold filled with fibrin gel, mesenchymal stem cells (MSCs) and poly(ethylene oxide)-b-poly (L-lysine) (PEO-b-PLL)/pDNA-TGF-β1 complexes was fabricated and applied in vivo for synchronized regeneration of cartilage and subchondral bone. The PEO-b-PLL/pDNA-TGF-β1 complexes could transfect MSCs in vitro to produce TGF-β1 in situ and up regulate the expression of chondrogenesis-related genes in the construct. The expression of heterogeneous TGF-β1 in vivo declined along with the prolongation of implantation time, and lasted for 3 and 6 weeks in the mRNA and protein levels, respectively. The constructs (Experimental group) of PLGA/fibrin gel/MSCs/(PEO-b-PLL/pDNA-TGF-β1 complexes) were implanted into the osteochondral defects of rabbits to restore the functional cartilages, with gene-absent constructs as the Control. After 12 weeks, the Experimental group regenerated the neo-cartilage and subchondral bone with abundant deposition of glycosaminoglycans (GAGs) and type II collagen. The regenerated tissues had good integration with the host tissues too. By contrast, the defects were only partially repaired by the Control constructs. qRT-PCR results demonstrated that expression of the chondrogenesis-marker genes in the Experimental group was significantly higher than that of the Control group, and was very close to that of the normal cartilage tissue.

Two-dimensional (2D) metals are an emerging class of nanostructures that have attracted enormous research interest due to their unusual electronic and thermal transport properties. Adding mesopores in the plane of ultrathin 2D metals is the next big step in manipulating these structures because increasing their surface area improves the utilization of the material and the availability of active sites. Here, we report a novel synthetic strategy to prepare an unprecedented type of 2D mesoporous metallic iridium (Ir) nanosheet. Mesoporous Ir nanosheets can be synthesized with close-packed assemblies of diblock copolymer (poly-(ethylene oxide)- b-polystyrene, PEO- b-PS) micelles aligned in the 2D plane of the nanosheets. This novel synthetic route opens a new dimension of control in the synthesis of 2D metals, enabling new kinds of mesoporous architectures with abundant catalytically active sites. Because of their unique structural features, the mesoporous metallic Ir nanosheets exhibit a high electrocatalytic activity toward the oxygen evolution reaction (OER) in acidic solution as compared to commercially available catalysts.

Block copolymer vesicles can be turned into nanoreactors when a catalyst is encapsulated in these hollow nanostructures. However the membranes of these polymersomes are most often impermeable to small organic molecules, while applications as nanoreactor, as artificial organelles, or as drug-delivery devices require an exchange of substances between the outside and the inside of polymersomes. Here, a simple and versatile method is presented to render polymersomes semipermeable. It does not require complex membrane proteins or pose requirements on the chemical nature of the polymers. Vesicles made from three different amphiphilic block copolymers (α,ω-hydroxy-end-capped poly(2-methyl-2-oxazoline)-block-poly(dimethylsiloxane)-block-poly(2-methyl-2-oxazoline) (PMOXA-b-PDMS-b-PMOXA), α,ω-acrylate-end-capped PMOXA-b-PDMS-b-PMOXA, and poly(ethylene oxide)-block-poly(butadiene) (PEO-b-PB)) were reacted with externally added 2-hydroxy-4'-2-(hydroxyethoxy)-2-methylpropiophenone under UV-irradiation. The photoreactive compound incorporated into the block copolymer membranes independently of their chemical nature or the presence of double bonds. This treatment of polymersomes resulted in substantial increase in permeability for organic compounds while not disturbing the size and the shape of the vesicles. Permeability was assessed by encapsulating horseradish peroxidase into vesicles and measuring the accessibility of substrates to the enzyme. The permeability of photoreacted polymersomes for ABTS, AEC, pyrogallol, and TMB was determined to be between 1.9 and 38.2 nm s(-1). It correlated with the hydrophobicity of the compounds. Moreover, fluorescent dyes were released at higher rates from permeabilized polymersomes compared to unmodified ones. The permeabilized nanoreactors retained their ability to protect encapsulated biocatalysts from degradation by proteases.

BACKGROUND

Progressive external ophthalmoplegia (PEO) is a mitochondrial disorder associated with defective enzymatic activities of oxidative phosphorylation (OXPHOS), depletion of mitochondrial DNA (mtDNA) and/or accumulation of mtDNA mutations and deletions. Recent positional cloning studies have linked the disease to four different chromosomal loci. Mutations in POLG1 are a frequent cause of this disorder.

METHODS

We describe two first-cousins: the propositus presented with PEO,mitochondrial myopathy and neuropathy, whereas his cousin showed a Charcot- Marie-Tooth phenotype. Neurophysiological studies, peroneal muscle and sural nerve biopsies, and molecular studies of mtDNA maintenance genes (ANT1, Twinkle, POLG1, TP) and non dominant CMT-related genes (GDAP1, LMNA, GJB1) were performed.

RESULTS

A severe axonal degeneration was found in both patients whereas hypomyelination was observed only in the patient with PEO whose muscle biopsy specimen also showed defective OXPHOS and multiple mtDNA deletions. While no pathogenetic mutations in GDAP1, LMNA, and GJB1 were found, we identified a novel homozygous POLG1 mutation (G763R) in the PEO patient. The mutation was heterozygous in his healthy relatives and in his affected cousin.

CONCLUSIONS

A homozygous POLG1 mutation might explain PEO with mitochondrial abnormalities in skeletal muscle in our propositus, and it might have aggravated his axonal and hypomyelinating sensory-motor neuropathy. Most likely, his cousin had an axonal polyneuropathy with CMT phenotype of still unknown etiology.

In this work, the degradation of hydroxychloroquine (HCQ) drug in aqueous solution by electrochemical advanced oxidation processes including electrochemical oxidation (EO) using boron doped diamond (BDD) and its combination with UV irradiation (photo-assisted electrochemical oxidation, PEO) and sonication (sono-assisted electrochemical oxidation, SEO) was investigated. EO using BDD anode achieved the complete depletion of HCQ from aqueous solutions in regardless of HCQ concentration, current density, and initial pH value. The decay of HCQ was more rapid than total organic carbon (TOC) indicating that the degradation of HCQ by EO using BDD anode involves successive steps leading to the formation of organic intermediates that end to mineralize. Furthermore, the results demonstrated the release chloride (Cl^-) ions at the first stages of HCQ degradation. In addition, the organic nitrogen was converted mainly into NO₃ ^- and NH₄ ⁺ and small amounts of volatile nitrogen species (NH₃ and NO_x). Chromatography analysis confirmed the formation of 7-chloro-4-quinolinamine (CQLA), oxamic and oxalic acids as intermediates of HCQ degradation by EO using BDD anode. The combination of EO with UV irradiation or sonication enhances the kinetics and the efficacy of HCQ oxidation. PEO requires the lowest energy consumption (EC) of 63 kWh/m³ showing its cost-effectiveness. PEO has the potential to be an excellent alternative method for the treatment of wastewaters contaminated with HCQ drug and its derivatives.

Keywords: Boron doped diamond; Electrochemical oxidation; Hydroxychloroquine; Hydroxyl radicals; Specific energy consumption; UV irradiation.

Novel poly (ethylene oxide) (PEO) hydrogel films were synthesized via UV cross-linking with pentaerythritol tetra-acrylate (PETRA) as cross-linking agent. The purpose of this work was to develop a novel hydrogel film suitable for passive transdermal drug delivery via skin application. Hydrogels were loaded with model drugs (lidocaine hydrochloride (LID), diclofenac sodium (DIC) and ibuprofen (IBU)) via post-loading and in situ loading methods. The effect of loading method and drug physicochemical properties on the material and drug release properties of medicated film samples were characterized using scanning electron microscopy (SEM), swelling studies, differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR), tensile testing, rheometry, and drug release studies. In situ loaded films showed better drug entrapment within the hydrogel network and also better polymer crystallinity. High drug release was observed from all studied formulations. In situ loaded LID had a plasticizing effect on PEO hydrogel, and films showed excellent mechanical properties and prolonged drug release. The drug release mechanism for the majority of medicated PEO hydrogel formulations was determined as both drug diffusion and polymer chain relaxation, which is highly desirable for controlled release formulations.

In this study, the formation and disintegration of polyelectrolyte complex micelles is studied by dynamic light scattering titrations with the aim to assess the extent to which these complexes equilibrate. Also, the time evolution of samples at fixed (electroneutral) composition was followed to obtain information about the relaxation time of the complex formation. We find that, in 3.5 mM phosphate buffer with pH 7, polyelectrolyte complex micelles consisting of the positively charged homopolymer PDMAEMA(150), the negatively charged diblock copolymer PAA(42)-PAAm(417) (both having a pH-dependent charge), as well as the positively charged protein lysozyme slowly equilibrate with a relaxation time of about 2 days. The same structures were obtained, independent of the way the polymers and proteins had been mixed. In contrast, polyelectrolyte complex micelles (at the same pH) consisting of (pH-dependent) negatively charged homopolymer PAA(139), the pH-independent positively charged diblock copolymer P2MVP(41)-PEO(205), and the negatively charged protein alpha-lactalbumin did not equilibrate. The way in which solutions containing these macromolecules were mixed yielded different results that did not change over the period of at least a week.

Variations in the mitochondrial helicase Twinkle (PEOPEO). We describe five patients from two unrelated Alsatian families with the new R374W variation in the Twinkle linker region who progressively developed an autosomal dominant multisystem disorder with PEO, hearing loss, myopathy, dysphagia, dysphonia, sensory neuropathy, and late-onset dementia resembling Alzheimer's disease. These observations demonstrate that Twinkle variations in the linker domain alter cerebral function and further implicate disrupted mitochondrial DNA integrity in the pathogenesis of dementia.

We present a method for organizing metallic nanoparticles in solution that is based on the hydrophobic effect and does not require either hydrogen bonding or molecular recognition. When amphiphilic V-shaped molecules are attached to a gold cluster, an aggregation process ensues in aqueous solution and leads to the formation of well-defined cylindrical and vesicular nanoarrays of particles. The metallic clusters densely pack at the boundary separating the hydrophobic core from the hydrophilic corona of the hybrid micelle-like aggregates. This design allows one to assemble and disassemble the nanoparticles in a reversible manner and control the size and the morphology of the arrays by changing the conditions of the solution preparation. The versatility of this method is demonstrated by its applicability to different metals with covalently attached amphiphilic arms with various chemical compositions (PS-PEO and PB-PEO) and molecular weights.

When mitochondrial diseases result from mutations found in the mitochondrial DNA, engineered mitochondrial-targeted nucleases such as mitochondrial-targeted zinc finger nucleases are shown to specifically eliminate the mutated molecules, leaving the wild-type mitochondrial DNA intact to replicate and restore normal copy number. In this issue, Gammage and colleagues successfully apply this improved technology on patients' cells with two types of genetic alterations responsible for neuropathy ataxia and retinitis pigmentosa (NARP) syndrome and Kearns Sayre syndrome and progressive external ophthalmoplegia (PEO).

The objective of the study was to prepare and characterize the domperidone (DOM) hot-melt extruded (HME) buccal films by both in vitro and in vivo techniques. The HME film formulations contained PEO N10 and/or its combination with HPMC E5 LV or Eudragit RL100 as polymeric carriers, and PEG3350 as a plasticizer. The blends were co-processed at a screw speed of 50 rpm with the barrel temperatures ranging from 120-160°C utilizing a bench top co-rotating twin-screw hot-melt extruder using a transverse-slit die. The HME films were evaluated for drug content, drug excipient interaction, in vitro drug release, mechanical properties, in vivo residence time, in vitro bioadhesion, swelling and erosion, ex vivo permeation from HME films and the selected optimal formulation was subjected for bioavailability studies in healthy human volunteers. The extruded films demonstrated no drug excipient interaction and excellent content uniformity. The selected HME film formulation (DOM2) exhibited a tensile strength (0.72 Kg/mm(2)), elongation at break (28.4% mm(2)), in vivo residence time (120 min), peak detachment force (1.55 N), work of adhesion (1.49 mJ), swelling index (210.2%), erosion (10.5%) and in vitro drug release of 84.8% in 2 h. Bioavailability from the optimized HME buccal films was 1.5 times higher than the oral dosage form and the results showed statistically significant (p < 0.05) difference. The ex vivo-in vivo correlation was found to have biphasic pattern and followed type A correlation. The results indicate that HME is a viable technique for the preparation of DOM buccal-adhesive films with improved bioavailability characteristics.

A new method was developed for binding poly-(ethylene oxide) (PEO) to polymer surfaces that involves the use of electron beam irradiation in two steps. In the first, methacrylic acid was grafted and polymerized to a polymer surface, changing it from hydrophobic to hydrophilic. Exposure of this surface to aqueous PEO solutions resulted in strong hydrogen bonding of the PEO, which was covalently grafted in a second radiation step. The PEO grafts were stable; they could not be removed with extensive washing with water, soaking in basic solution, or gentle mechanical scraping. Both monolayers and multilayers of PEO were formed. The density of the monolayers were found to have little dependence on the molecular weight or concentration of the PEO solution; multilayers could be controlled by varying the viscosity of the PEO solution and the method of application. The PEO-grafted monolayers were tested for their ability to prevent protein adsorption of cytochrome-c, albumin, and fibronectin. Monolayers of star PEO were the most effective, at best showing a 60% decrease in adsorption from untreated controls. One million molecular wight linear PEO monolayers were almost as effective as star monolayers, and 35,000 g/mol linear PEO was bound too closely to the surface, owing to its small size, to have much impact in preventing protein adsorption. The reason for the continued protein adsorption was believed to be due to a close grafting of the PEO to the surface, as well as the grafted methacrylic acid chains being long enough to extend through the PEO monolayer, thus being accessible on the surface.

The aim of this work was to develop a tablet for the buccal delivery of the poorly soluble drug carvedilol (CAR), based on poly(ethyleneoxide) (PEO) as bioadhesive sustained-release platform and hydroxypropyl-beta-cyclodextrin (HPbetaCD) as modulator of drug release. As first, PEO tablets loaded with CAR/HPbetaCD binary systems with different dissolution properties were tested for CAR and HPbetaCD release features and compared to PEO tablets containing only CAR. When the drug was incorporated as CAR/HPbetaCD freeze-dried product, all CAR content was released from the tablet in about 10 h, displaying a constant release regimen after a transient. The effect of HPbetaCD incorporation on the release mechanism, was rationalized on the basis of the interplay of different physical phenomena: erosion and swelling of the tablet, drug dissolution, drug counter-diffusion and complex formation. In the second part of the study, the potential of HPbetaCD-containing PEO tablets as buccal delivery system for CAR was tested. It was found that the incorporation of HPbetaCD in the tablet did not alter significantly its good adhesion properties. The feasibility of buccal administration of CAR was assessed by permeation experiments on pig excised mucosa. The amount of CAR permeated from PEO tablet was higher in the case of HPbetaCD-containing tablets, the maximum value being obtained for CAR/HPbetaCD freeze-dried system. Our results demonstrate that, when the tablet is employed as transmucosal system, the role of drug dissolution enhancement in the hydrated tablet is much more relevant than in solution for increasing the delivery rate.

A simple, versatile, protein-repulsive, substrate-independent biomimetic surface modification is presented that is based on the creation of a PEO brush on a polydopamine anchoring layer and its capacity for selective follow-up modifications with various ligands using a copper-catalyzed alkyne-azide cycloaddition reaction. The desired surface concentration of peptide biomimetic ligands can be controlled by adjusting the peptide concentration in the reaction mixture, then measuring the activity of (125)I-radiolabeled peptides that are immobilized on the substrates. The performance of the prepared substrates is tested in cell cultures with MEF cells and a human ECC line.

OBJECTIVE

Simple uncoated compressed tablets with a central hole (donut-shape) are proposed to provide a constant drug release over a long period of time >> 20 hrs). The effect of hole size and drug solubility on the release kinetics is investigated.

METHODS

The donut-shaped polyethylene oxide (PEO, Mw = 4 x 10(6)) tablets (600 mg and 12 mm diameter) are bored with a drill bit (3/32", 7/64", 1/8", and 5/32").

RESULTS

The release of theophylline from the donut-shaped tablets is zero order (80-90% release) before rapidly decreasing. As the hole size is increased from 7/64" to 5/32", the release rate increases and the release time is shortened. However, the release of theophylline from the donut-shaped tablet with a hole size of 3/32" follows the same anomalous release profile from a tablet without a hole. As drug solubility increases, the duration of linear drug release is shortened to 65-70% release followed by a severe tailing at the later stage of the release.

CONCLUSIONS

Donut-shaped PEO tablets with a hole provide zero-order release kinetics because the effect of the releasing surface area on the release kinetics is reduced.

A new electrospinning apparatus was developed to generate nanofibrous materials with improved organizational control. The system functions by oscillating the deposition signal (ODS) of multiple collectors, allowing significantly improved nanofiber control by manipulating the electric field which drives the electrospinning process. Other electrospinning techniques designed to impart deposited fiber organizational control, such as rotating mandrels or parallel collector systems, do not generate seamless constructs with high quality alignment in sizes large enough for medical devices. In contrast, the ODS collection system produces deposited fiber networks with highly pure alignment in a variety of forms and sizes, including flat (8 × 8 cm(2)), tubular (1.3 cm diameter), or rope-like microbundle (45 μm diameter) samples. Additionally, the mechanism of our technique allows for scale-up beyond these dimensions. The ODS collection system produced 81.6 % of fibers aligned within 5° of the axial direction, nearly a four-fold improvement over the rotating mandrel technique. The meshes produced from the 9 % (w/v) fibroin/PEO blend demonstrated significant mechanical anisotropy due to the fiber alignment. In 37 °C PBS, aligned samples produced an ultimate tensile strength of 16.47 ± 1.18 MPa, a Young's modulus of 37.33 MPa, and a yield strength of 7.79 ± 1.13 MPa. The material was 300 % stiffer when extended in the direction of fiber alignment and required 20 times the amount of force to be deformed, compared to aligned meshes extended perpendicular to the fiber direction. The ODS technique could be applied to any electrospinnable polymer to overcome the more limited uniformity and induced mechanical strain of rotating mandrel techniques, and greatly surpasses the limited length of standard parallel collector techniques.

This research described a novel composite electrospun nanofibers, which were consisted of MPEG-b-PLA micelles, chitosan, and PEO, realizing controlled release of both hydrophobic and hydrophilic drugs. 5-FU and Cefradine used as model drugs were successfully loaded in the nanofibers. The in vitro studies showed there was a low initial burst release of 5-FU from micelles-loaded nanofibers, and the final release proportion was about 91.4% after continually releasing for 109 h. In vitro cytotoxicity studies revealed that 5-FU-loaded nanofibers restrained HepG-2 cells efficiently, and the cell viability was 45.9% after three days of cultivation in solutions containing micelles-loaded nanofibers with 21.6 μg 5-FU. All results suggested that micelles-loaded nanofibers with two kinds of drugs can be used as an effective controlled drug delivery vehicle and may have a bright future in cancer chemotherapy or clinical treatments.

In this study, composite scaffolds were prepared with polyethylene oxide (PEO)-linked gelatin and tricalcium phosphate (TCP). Chitosan, a positively charged polysaccharide, was introduced into the scaffolds to improve the properties of the artificial bone matrix. The chemical and thermal properties of composite scaffolds were investigated by Fourier transform infrared spectroscopy, thermogravimetric analyzer, differential thermal analyzer. In vitro cytotoxicity of the composite scaffold was also evaluated and the sample showed no cytotoxic effect. The morphology was studied by SEM and light microscopy. It was observed that the prepared scaffold had an open interconnected porous structure with pore size of 230-354 μm, which is suitable for osteoblast cell proliferation. The mechanical properties were assessed and it was found that the composite had compressive modulus of 1200 MPa with a strength of 5.2 MPa and bending modulus of 250 MPa having strength of 12.3 MPa. The porosity and apparent density were calculated and it was found that the incorporation of TCP can reduce the porosity and water absorption. It was revealed from the study that the composite had a 3D porous microstructure and TCP particles were dispersed evenly among the crosslinked gelatin/chitosan scaffold.

The objective of the present research was to investigate the stability of an amorphous drug, Delta(9)-tetrahydrocannabinol (THC) in polymer-based transmucosal systems. THC was incorporated in polyethylene oxide and hydroxypropylcellulose matrices by a hot-melt fabrication procedure, utilizing various processing aids. The chemical stability of the drug in the polymeric matrices was investigated with respect to processing temperature, processing time, formulation additives, and storage conditions. HPLC analysis of the THC-loaded systems indicated that the extent of drug degradation was influenced by all of the above mentioned variables. THC was particularly unstable in the vitamin E succinate-processed films, indicating a potential incompatibility. Thermal stability of the drug, polymers, and other ingredients at the elevated processing temperatures during the fabrication procedure, was evaluated using the isothermal mode of thermo-gravimetric analysis. When held at 160 and 200 degrees C, the weight percentage of THC decreased linearly as a function of time. Weight loss was controlled by blending the drug with polymers, PEO and HPC, of which PEO was determined to be more effective. Although higher temperatures lowered the polymer melt viscosity, THC and other materials were chemically and thermally unstable at such high temperatures. Due to this, matrix fabrication was found to be favorable at relatively lower temperatures, such as 120 degrees C.

Curcumin, a naturally occurring drug molecule, has been extensively investigated for its various potential usages in medicine. Its water insolubility and high metabolism rate require the use of drug delivery systems to make it effective in the human body. Among various types of nanocarriers, block copolymer based ones are the most effective. These polymers are broadly used as drug-delivery systems, but the nature of this process is poorly understood. In this paper, we propose a molecular dynamics simulation study of the interaction of Curcumin with block copolymer based on polyethylene oxide (PEO) and polypropylene oxide (PPO). The study has been conducted considering the smallest PEO and PPO oligomers and multiple chains of the block copolymer Pluronic P85. Our study shows that the more hydrophobic 1,2-dimethoxypropane (DMP) molecules and PPO block preferentially coat the Curcumin molecule. In the case of the Pluronic P85, simulation shows formation of a drug-polymer aggregate within 50 ns. This process leaves exposed the PEO part of the polymers, resulting in better solvation and stability of the drug in water.