Mesoporous Silica Nanoparticles as a Potential Nanoplatform: Therapeutic Applications and Considerations.

With advances in nanotechnology, nanoparticles have come to be regarded as carriers of therapeutic agents and have been widely studied to overcome various diseases in the biomedical field. Among these particles, mesoporous silica nanoparticles (MSNs) have been investigated as potential nanocarriers to deliver drug molecules to various target sites in the body. This review introduces the physicochemical properties of MSNs and synthesis procedures of MSN-based nanoplatforms. Moreover, we focus on updating biomedical applications of MSNs as a carrier of therapeutic or diagnostic cargo and review clinical trials using silica-nanoparticle-based systems. Herein, on the one hand, we pay attention to the pharmaceutical advantages of MSNs, including nanometer particle size, high surface area, and porous structures, thus enabling efficient delivery of high drug-loading content. On the other hand, we look through biosafety and toxicity issues associated with MSN-based platforms. Based on many reports so far, MSNs have been widely applied to construct tissue engineering platforms as well as treat various diseases, including cancer, by surface functionalization or incorporation of stimuli-responsive components. However, even with the advantageous aspects that MSNs possess, there are still considerations, such as optimizing physicochemical properties or dosage regimens, regarding use of MSNs in clinics. Progress in synthesis procedures and scale-up production as well as a thorough investigation into the biosafety of MSNs would enable design of innovative and safe MSN-based platforms in biomedical fields.

Development and characterization of a superabsorbing hydrogel film containing Ulmus davidiana var. Japonica root bark and pullulan for skin wound healing.

Ulmus davidiana var. japonica (UD) has widely been used in Korean traditional medicine for the treatment of various types of diseases including inflammation and skin wounds. The UD root bark powders possess gelling activity with an excellent capacity for absorbing water. This distinct property could make the UD root bark powders to be a great material for manufacturing a gel film specifically for the healing of large and highly exudating wounds (e.g., pressure sores and diabetic ulcers). In this research, we separated the UD root bark powder into 4 different samples based on their sizes and then tested their water absorption capacity and flowability. Based on these results, 75-150 µm sized and below 75 µm sized samples of UD root bark powders were chosen, and UD gel films were prepared. The UD gel films showed good thermal stability and mechanically improved properties compared with pullulan only gel film with excellent swelling capacity and favorable skin adhesiveness. Further, in the animal studies with the skin wound mice model, the UD gel films exhibited significant therapeutic effects on accelerating wound closure and dermal regeneration. Overall, this study demonstrated the applicability of UD root bark powders for hydrogel wound dressing materials, and the potential of UD gel films to be superior wound dressings to currently available ones.

Enhanced Solubility, In-Vitro Dissolution and Lipase Inhibition of a Self-Nanoemulsifying Drug Delivery System Containing Orlistat.

The aim of this work was to prepare and assess a self-nanoemulsifying drug delivery system (SNEDDS) containing water-insoluble orlistat that was used for the inhibition of lipase activity in gastrointestinal lumen. The pseudo-ternary phase diagram, composed of orlistat and medium chain triglycerides (MCT) as oil phase and Cremophor EL as surfactant, was made for the confirmation of giving SNEDDS preconcentrate. The physical state, particle size dispersed in water, dissolution and lipase inhibition of SNEDDS preconcentrates were investigated. The appointed SNEDDS preconcentrates in the pseudo-ternary phase diagram showed no endothermic peak of orlistat and a liquid state. The particle sizes of SNEDDS dispersed with water were uniform and in the range of <200 nm. In the dissolution test, the liquid SNEDDS preconcentrate and solid state mixture exhibited 90.89±2.03% versus 22.42±3.71% at 60 min., respectively, whereas the raw orlistat showed no significant dissolution rate. The SNEDDS preconcentrate showed a lipase inhibition of 92.42±1.58% until 60 min., with no significant inhibition activity of orlistat. Therefore, the SNEDDS preconcentrate presented in this work solubilized orlistat and increased its dissolution rate, and resulted in sufficient inhibitory action on lipase.

The quality of medicines for the prevention and management of hypertensive disorders of pregnancy: A systematic review.

The quality of medicines for the prevention and management of hypertensive disorders of pregnancy globally is a critical challenge in the reduction of maternal mortality rate. We aimed to conduct a systematic review of available studies on the quality of the eight medicines recommended globally for the prevention and management of hypertensive disorders of pregnancy. We searched five electronic databases- Ovid MEDLINE, EMBASE, CINAHL, ProQuest and Cochrane Library, and also grey literature, without year or language limitations. Any study assessing the quality parameters (Active Pharmaceutical Ingredients, pH, sterility, solubility, impurities) of medicines by using any valid laboratory methods was eligible. Two reviewers independently screened the studies, extracted data and applied Medicine Quality Assessment Reporting Guidelines tool for quality assessment. Results were narratively reported and stratified by the drug types. Of 5669 citations screened, 33 studies from 27 countries were included. Five studies reported on the quality of magnesium sulphate-two (Nigeria and USA) found substandard medicine due to failing API specification and contaminants, respectively. Another study from Nigeria and a multi-country study (10 lower-middle- and low-income countries) found poor-quality due to failing the pH criteria. Seven of eight studies evaluating aspirin found quality issues, including degraded medicines in five studies (Brazil, USA, Yugoslavia and Pakistan). Five studies of calcium supplements found quality issues, particularly heavy metal contamination. Of 15 antihypertensives quality studies, 12 found substandard medicines and one study identified counterfeit medicines. This systematic review identified pervasive issues of poor-quality medicines across all recommended medicines used to prevent or treat hypertensive disorders of pregnancy, raising concerns regarding their safety and effectiveness.

An enhanced algorithm for improving real-time video transmission for tele-training education.

Tele-training in surgical education has not been effectively implemented. There is a stringent need for a high transmission rate, reliability, throughput, and reduced distortion for high-quality video transmission in the real-time network. This work aims to propose a system that improves video quality during real-time surgical tele-training. The proposed approach aims to minimise the video frame's total distortion, ensuring better flow rate allocation and enhancing the video frames' reliability. The proposed system consists of a proposed algorithm for Enhancing Video Quality, Distorting Minimization, Bandwidth efficiency, and Reliability Maximization called (EVQDMBRM) algorithm. The proposed algorithm reduces the video frame's total distortion. In addition, it enhances the video quality in a real-time network by dynamically allocating the flow rate at the video source and maximizing the transmission reliability of the video frames. The result shows that the proposed EVQDMBRM algorithm improves the video quality with the minimized total distortion. Therefore, it improves the Peak Signal to Noise Ratio (PSNR) average by 51.13 dB against 47.28 dB in the existing systems. Furthermore, it reduces the video frames processing time average by 58.2 milliseconds (ms) against 76.1, and the end-to-end delay average by 114.57 ms against 133.58 ms comparing to the traditional methods. The proposed system concentrates on minimizing video distortion and improving the surgical video transmission quality by using an EVQDMBRM algorithm. It provides the mechanism to allocate the video rate at the source dynamically. Besides that, it minimizes the packet loss ratio and probing status, which estimates the available bandwidth.

Potential Albumin-Based Antioxidant Nanoformulations for Ocular Protection against Oxidative Stress.

Amongst various drug administration methods, ophthalmic drug delivery has been a useful way for the treatment of eye-related diseases. However, therapeutic efficacy of ocular therapy for anterior or posterior eye segments through topical administration is considerably challenged by the number of anatomical and physiological barriers in the eyes affecting ocular bioavailability. In this respect, advanced biocompatible nanoformulations make it possible to improve drug delivery to the target sites and enhance ocular bioavailability of ophthalmic medicines. Various ocular diseases have been reported to be related to oxidative stresses in tissues, and polyphenolic compounds have been known for their antioxidant activities in various tissues, including the eyes. Despite drug efficacy, poor water solubility and intrinsic color of the compounds limit the drug's inclusion into the development of ocular medicine. In the present study, we investigated the antioxidant protectant efficacy of rosmarinic or ursolic acid in the retinal epithelial cells, as compared to those of curcumin, by forming nanospheres with bovine serum albumin. Our results demonstrate that antioxidant-containing nanoformulations provide a significantly higher drug solubility and decreased ROS (reactive oxygen species) production in the retinal epithelial cells. Finally, we also found that albumin-based nanoformulations could improve bioavailability and increase antioxidant activity of rosmarinic or ursolic acid in the retina to be applied as efficient ocular protectant.

Preclinical Evaluation of UDCA-Containing Oral Formulation in Mice for the Treatment of Wet Age-Related Macular Degeneration.

As a posterior ocular disease, wet age-related macular degeneration (WAMD) has been known to be related to vision loss, accompanying ocular complications. The intravitreous injection of VEGF antibodies has been reported to be an effective treatment to relieve symptoms of WAMD. However, the limitations of this treatment are high costs and invasiveness. For this reason, oral delivery route can be considered as a cost-effective way and the safest method to deliver drug molecules to the eyes. Accordingly, ursodeoxycholic acid (UDCA) was included in the oral formulation as the potential substance for the cure of WAMD in the animal model. Various pharmacological activities, such as antioxidant or anti-inflammatory effects, have been reported for UDCA and recent reports support the effects of UDCA in ocular treatment. However, due to poor water solubility and low pKa (around 5.0), it has been challenging to formulate aqueous solution of UDCA in the neutral pH range. In the present study, we confirmed the aqueous solubility of the oral UDCA formulation and performed a preclinical study, including pharmacokinetic profiling and WAMD model efficacy study in mice after oral administration of the drug solution. The results demonstrated that the formulation improved bioavailability of UDCA and efficiently delivered UDCA to the eye tissues after oral absorption. UDCA formulation was found to have inhibitory effects of choroidal neovascularization with a functional recovery in mice retinas. Taken together, our results suggest that the oral UDCA formulation could be used as a potent supplement for the cure of WAMD and related retinal diseases.

Evaluation of epithelial transport and oxidative stress protection of nanoengineered curcumin derivative-cyclodextrin formulation for ocular delivery.

Ocular drug delivery has been a well-known route for the drug administration for the treatment of ocular diseases. However, numerous anatomical and physiological barriers prevailing in the eye itself create considerable challenges for achieving the necessitated therapeutic efficacy along with ocular bioavailability. However, recent advances in nanoengineered strategies hold definite promises in terms of devising improved ophthalmic medicines for the effective drug delivery to target the sites with enhanced ocular bioavailability. Curcumin, a hydrophobic polyphenol yellow colored compound, and its metabolic reduced product, tetrahydrocurcumin (THC), have been known for their beneficial pharmacological functions, such as anti-inflammatory or anti-oxidant activities at various tissue sites. However, the low aqueous solubility of these compounds results in their poor bioavailability, thereby limiting their widespread application. Therefore, in the present study, we investigated the changes in drug solubility by forming inclusion complexes with different derivatives of hydroxypropyl (HP)-cyclodextrins (CD). To this end, the spray drying technique was used for nanoengineering curcumin or THC-loaded formulations to improve the stability of formulations during the storage. The formulations were characterized in terms of physicochemical properties and cellular permeability. The results demonstrated that the encapsulation of curcumin (or THC) into the HP-CDs significantly increased the drug solubility and enhanced the corneal and retinal epithelial permeability. Curcumin or THC complexes in HP-CDs with improved bioavailability also induced anti-oxidant activity (SOD1, CAT1, and HMOX1) in higher levels in the ocular epithelial cells and showed oxidative protection effects in rabbit cornea tissues that will boost up their application in ocular medicine.

Pro-apoptotic peptides-based cancer therapies: challenges and strategies to enhance therapeutic efficacy.

Cancer is a leading cause of death worldwide. Despite many advances in the field of cancer therapy, an effective cure is yet to be found. As a more potent alternative for the conventional small molecule anti-cancer drugs, pro-apoptotic peptides have emerged as a new class of anticancer agents. By interaction with certain members in the apoptotic pathways, they could effectively kill tumor cells. However, there remain bottleneck challenges for clinical application of these pro-apoptotic peptides in cancer therapy. In this review, we will overview the developed pro-apoptotic peptides and outline the widely adopted molecular-based and nanoparticle-based strategies to enhance their anti-tumor effects.

Orlistat-loaded solid SNEDDS for the enhanced solubility, dissolution, and in vivo performance.

BACKGROUND: The present study aimed to develop orlistat-loaded solid self-nanoemulsifying drug delivery system preconcentrate (SSP) with the minimum use of lipid excipients for the enhanced solubility, in vitro dissolution, lipase inhibition, and in vivo performance. MATERIALS AND METHODS: In the screening of solubilizing vehicles, Solutol HS15 and Lauroglycol 90 were selected as the surfactant and oil phase, respectively. A pseudo-ternary phase diagram composed of Solutol HS15, Lauroglycol 90, and orlistat as an anti-obesity agent and lipid component was constructed, and the SSP regions were confirmed in terms of the particle size distribution in water, melting point by differential scanning calorimetry, and crystallinity by X-ray diffraction. RESULTS: Physicochemical interaction between Solutol HS15 and orlistat resulted in SSP with various melting points in the range of 26°~33°C. The representative maximum orlistat-loaded SSP (orlistat/Solutol HS15/Lauroglycol 90=55/40/5, weight ratio) showed the melting point of 32.23°C and constructed uniform nanoemulsion with the particle size of 141.7±1.1 nm dispersed in water. In the dissolution test at pH 1.2 without any detergent, the SSP reached 98.12%±0.83% until 45 minutes, whereas raw orlistat showed no significant dissolution rate. The dissolution samples containing SSP showed a lipase inhibition of 90.42%±1.58% within 45 minutes. In terms of the reduction level of fat absorption in rats, the intake group of SSP gave a significantly higher fat excretion into stool than the one observed in the raw orlistat group (P<0.05). CONCLUSION: In conclusion, the suggested novel SSP formulation would be an effective and promising candidate for the treatment of obesity.

High rates of multidrug resistance among uropathogenic Escherichia coli in children and analyses of ESBL producers from Nepal.

BACKGROUND: Emergence of Extended-spectrum beta-lactamase producing Escherichia coli causing urinary tract infections (UTI) among pediatric patients is an increasing problem worldwide. However, very little is known about pediatric urinary tract infections and antimicrobial resistance trend from Nepal. This study was conducted to assess the current antibiotic resistance rate and ESBL production among uropathogenic Escherichia coli in pediatric patients of a tertiary care teaching hospital of Nepal. METHODS: A total of 5,484 urinary tract specimens from children suspected with UTI attending a teaching hospital of Nepal over a period of one year were processed for the isolation of bacterial pathogens and their antimicrobial susceptibility testing. Escherichia coli (n = 739), the predominant isolate in pediatric UTI, was further selected for the detection of ESBL-production by phenotypic combination disk diffusion test. RESULTS: Incidence of urinary tract infection among pediatric patients was found to be 19.68% and E coli (68.4%) was leading pathogen involved. Out of 739 E coli isolates, 64.9% were multidrug resistant (MDR) and 5% were extensively drug resistant (XDR). Extended spectrum beta lactamase (ESBL) was detected in 288 (38.9%) of the E coli isolates. CONCLUSION: Alarming rate of drug resistance among pediatric uropathogens and high rate of ESBL-producing E. coli was observed. It is extremely necessary to routinely investigate the drug resistance among all isolates and formulate strict antibiotics prescription policy in our country.

Emerging Perils of Extended Spectrum ß-Lactamase Producing Enterobacteriaceae Clinical Isolates in a Teaching Hospital of Nepal.

Introduction. Infections due to extended spectrum ß-lactamase producing Enterobacteriaceae are on the rise. They pose serious public health problems due to their resistance to large number of antibiotics. However, little is known about the genotypes of ESBL from Nepal. Therefore, the study presents results of phenotypic and molecular characterization of ESBL producing Escherichia coli and Klebsiella spp. isolated from various clinical specimens in a tertiary care teaching hospital of Nepal. Methods. A total of 172 Enterobacteriaceae clinical isolates recovered from various clinical specimens were analyzed for their antibiotic susceptibility test. Detection of ESBLs was carried out using combination disk test and multiplex PCR for their genotypes (CTX-M, SHV, and TEM). Results. Out of 172 clinical isolates, 70 (40.6%) of them were found ESBL producers. The major source of ESBL producers was urinary tract samples and the highest ESBL production was observed in Escherichia coli (46.5%). Among ESBL genotypes, CTX-M (91.4%) was most predominant, followed by TEM (65.7%) and SHV (11.4%) in both of the isolates. Conclusions. High level of drug resistance and ESBL production was observed among the clinical isolates. There is a need for longitudinal and nationwide surveillance for drug resistance in clinical isolates and antimicrobial stewardship is necessary to guide the appropriate and judicious antibiotic use.