Thiolated Polymeric Hydrogels for Biomedical Applications: A Review.

Hydrogels are a three-dimensional (3D) network of hydrophilic polymers. The physical and chemical crosslinking of polymeric chains maintains the structure of the hydrogels even when they are swollen in water. They can be modified with thiol by thiol epoxy, thiol-ene, thiol-disulfide, or thiol-one reactions. Their application as a matrix for protein and drug delivery, cellular immobilization, regenerative medicine, and scaffolds for tissue engineering was initiated in the early 21st century. This review focuses on the ingredients, classification techniques, and applications of hydrogels, types of thiolation by different thiol-reducing agents, along with their mechanisms. In this study, different applications for polymers used in thiolated hydrogels, including dextran, gelatin, polyethylene glycol (PEG), cyclodextrins, chitosan, hyaluronic acid, alginate, poloxamer, polygalacturonic acid, pectin, carrageenan gum, arabinoxylan, carboxymethyl cellulose (CMC), gellan gum, and polyvinyl alcohol (PVA) are reviewed.

An Insight into the Role of Artificial Intelligence in the Early Diagnosis of Alzheimer's Disease.

BACKGROUND: The complication of Alzheimer's disease (AD) has made the development of its therapeutic a challenging task. Even after decades of research, we have achieved no more than a few years of symptomatic relief. The inability to diagnose the disease early is the major hurdle behind its treatment. Several studies have aimed to identify potential biomarkers that can be detected in body fluids (CSF, blood, urine, etc.) or assessed by neuroimaging (i.e., PET and MRI). However, the clinical implementation of these biomarkers is incomplete as they cannot be validated. METHODS: This study aimed to overcome the limitation of using artificial intelligence along with technical tools that have been extensively investigated for AD diagnosis. For developing a promising artificial intelligence strategy that can diagnose AD early, it is critical to supervise neuropsychological outcomes and imaging-based readouts with a proper clinical review. CONCLUSION: Profound knowledge, a large data pool, and detailed investigations are required for the successful implementation of this tool. This review will enlighten various aspects of early diagnosis of AD using artificial intelligence.

Fabrication of polyvinyl alcohol based fast dissolving oral strips of sumatriptan succinate and metoclopramide HCL.

Migraine is a throbbing condition, usually associated with nausea and vomiting and requires concurrent administration of anti-migraine along with anti-emetic therapy. The current study was undertaken with an aim to fabricate fast dissolving oral strips (FDOSs) containing Sumatriptan succinate (anti-migraine) and Metoclopramide HCl (anti-emetic) in combination without involving any superdisintegrant. Hydrophilic polymer polyvinyl alcohol (PVA) was used alone with three concentrations of 100, 125, and 150 mg using variable concentrations of glycerol. The solvent casting technique was employed to formulate FDOSs and were evaluated for surface morphology, mechanical properties, surface pH, % moisture content, disintegration time (DT), total dissolving time (TDT), drug contents, and dissolution profile. PVA (150 mg) with 5% glycerol concentration gave best formulation results. FDOSs have exhibited good tensile strength with smooth and uniform surface morphology. DT was ranged from 7.7 to 28 s; while TDT was from 26.4 to 77.6 s. Both polymer and plasticizer concentrations were found to be influencing the characteristics of the strips. Dissolution studies were carried out in distilled water for 15 min and all the formulations have shown released more than 50% drug within first 2 min thereby highlighting the usefulness of FDOSs for the delivery of both drugs in combination significantly. Optimized combination of ingredients was found to be suitable for the formulation of FDOSs for simultaneous delivery of Metoclopramide HCl and Sumatriptan succinate.

Nanoparticles Based Intranasal Delivery of Drug to Treat Alzheimer's Disease: A Recent Update.

Alzheimer Association Report (2019) stated that the 6th primary cause of death in the USA is Alzheimer's Disease (AD), which leads to behaviour and cognitive impairment. Nearly 5.8 million peoples of all ages in the USA have suffered from this disease, including 5.6 million elderly populations. The statistics of the progression of this disease is similar to the global scenario. Still, the treatment of AD is limited to a few conventional oral drugs, which often fail to deliver an adequate amount of the drug in the brain. The reduction in the therapeutic efficacy of an anti-AD drug is due to poor solubility, existence to the blood-brain barrier and low permeability. In this context, nasal drug delivery emerges as a promising route for the delivery of large and small molecular drugs for the treatment of AD. This promising pathway delivers the drug directly into the brain via an olfactory route, which leads to the low systemic side effect, enhanced bioavailability, and higher therapeutic efficacy. However, few setbacks, such as mucociliary clearance and poor drug mucosal permeation, limit its translation from the laboratory to the clinic. The above stated limitation could be overcome by the adaption of nanoparticle as a drug delivery carrier, which may lead to prolong delivery of drugs with better permeability and high efficacy. This review highlights the latest work on the development of promising Nanoparticles (NPs) via the intranasal route for the treatment of AD. Additionally, the current update in this article will draw the attention of the researcher working on these fields and facing challenges in practical applicability.

Rosuvastatin, Perindopril and Ezetimibe loaded instant release buccal films: Development and in vitro characterization.

BACKGROUND: Rosuvastatin Calcium and Ezetimibe are used to control cholesterol level while Perindopril Erbumine is used to treat hypertension. Hepatic metabolism reduces the therapeutic effect of these drugs. OBJECTIVE: Instant release buccal films (IRBFs) could possibly be a solution to this issue. The objective of the study was to formulate IRBFs of Rosuvastatin Calcium, Perindopril Erbumine and Ezetimibe using solvent casting technique. METHODS: Polymers used to prepare IRBFs included hydroxypropyl methylcellulose (HPMC E5), PEG 400 (as plasticizer) and Tween 80 (as surfactant). Solvent casting technique was used to fabricate the films, followed by their in-vitro analysis including high performance liquid chromatography (HPLC), X-ray diffraction (XRD), fourier transform infrared evaluation (FTIR), In-vitro dissolution, In-vitro disintegration, stability tests, scanning electron microscopy (SEM), folding fortitude, thickness evaluation, surface pH, tensile strength, weight variation and percentage moisture content. RESULTS: Optical microscopy as well as SEM analysis displayed that the surfaces of IRBFs were smooth with uniform mixing of ingredients. IRBFs disintegrated within 15 seconds while on dissolution they exhibited instant drug release i.e. 100% release in 2 minutes. CONCLUSIONS: The results show promising potential of IRBFs in drug delivery.

Development and optimization of flurbiprofen loaded microsponges; an in-vitro evaluation.

Current study was designed with the aim to employ quasi emulsification, and double emulsification techniques for the development of Flurbiprofen (FLB) loaded micro sponges, followed by their physicochemical evaluation. FTIR interpretations exhibited compatibility of ingredients, while crystallographic analysis revealed crystalline nature of pure drug, which was masked upon incorporation into microsponges. Optical microscope and SEM have exposed spherical and spongy surfaces of prepared micro sponges. Micromeritics suggested that the flow properties are excellent and microsponges have remarkable drug entrapment efficiency (98.55±0.08%). In-vitro dissolution studies demonstrated good control over release of FLB until 8th h from the prepared microsponges. However, a difference in cumulated amount of released drug was noticed i.e. EC based formulation has released about 99.3±0.10%, while XG facilitated EC based formulations offered 92.7±2.1% release of the drug. Zeta potential indicated access of negative charge while zeta sizer has described the range of the particle size between 2.6 to 3.5µm. Conclusively the results have advocated the suitability of selected ingredients for incorporation of FLB into microsponges for its sustained delivery.

Development of thiomer based buccal films for the enhancement of bioavailability: An in-vivo analysis.

Present work was conducted to improve the bioavailability of Tizanidine HCl (TZN) by formulating mucoadhesive buccal films (MBFs) using novel thiolated arabinoxylan (TAX) as film former. MBF's were prepared by solvent casting technique followed by their evaluation for surface morphology and folding endurance. Moreover, pharmacokinetic parameters including Cmax, tmax, t1/2 and AUC were determined after administering standard oral solution (SOS) and MBFs of TZN at a dose of 1mg/kg. Successful thiolation was confirmed by the presence of 4.98 to 7.04 mmol of thiol content per gram of the polymer. Results of in-vivo pharmacokinetics have signified (p=0.0089) the suitability of MBFs as a carrier of drug through buccal route. Results have explored that, t1/2 was increased from 2.51hrs (SOS) to 10 hrs, Cmax from 42.3 ng/ml (SOS) to 105ng/ml and tmax from 2hrs (SOS) to 6h. Conclusively, TAX has exhibited the potential to form MBFs thereby offering sustained release of TZN with improved pharmacokinetic profile.

Design, mechanism, delivery and therapeutics of canonical and Dicer-substrate siRNA.

Upon the discovery of RNA interference (RNAi), canonical small interfering RNA (siRNA) has been recognized to trigger sequence-specific gene silencing. Despite the benefits of siRNAs as potential new drugs, there are obstacles still to be overcome, including off-target effects and immune stimulation. More recently, Dicer substrate siRNA (DsiRNA) has been introduced as an alternative to siRNA. Similarly, it also is proving to be potent and target-specific, while rendering less immune stimulation. DsiRNA is 25-30 nucleotides in length, and is further cleaved and processed by the Dicer enzyme. As with siRNA, it is crucial to design and develop a stable, safe, and efficient system for the delivery of DsiRNA into the cytoplasm of targeted cells. Several polymeric nanoparticle systems have been well established to load DsiRNA for in vitro and in vivo delivery, thereby overcoming a major hurdle in the therapeutic uses of DsiRNA. The present review focuses on a comparison of siRNA and DsiRNA on the basis of their design, mechanism, in vitro and in vivo delivery, and therapeutics.

Antibiotic resistance pattern shown by various pathogens, causing infections in neonates.

This study was schemed to comprehend the latest kaleidoscopic trends of bacterial resistance in neonatal pathogens against all those antibiotics commonly employed as empirical therapy in neonates. The methodological approach included; isolation and subsequent identification of those pathogens having caused bacterial infections in neonates, application of antibiotic sensitivity testing and finally construing the conclusion depicting patterns of antibiotic resistance by various pathogens, isolated from neonatal biological samples. Antibiotic resistance patterns was evident in gram-positive as well as in gram-negative bacteria in all the eight species identified in this study. Even antibiotic drugs which are being commonly relied upon for treating multi-resistant bacterial infections, found to be in effective against many newly emerged resistant bacteria, when used alone. Resistance Antibiotics drugs against which most prominent resistance pattern emerged include; Amikacin sulphate, Linezolid, Piperacillin / Tazobactam, Amoxicillin / Clavulanic acid, Vencomycin, Cefoperazone / Sulbactam, Ceftriaxone sodium, Ciprofloxacin, Cefixime trihydrate and Imipenem. The inferred upshot suggests that antibiotic resistance is emerging fast and ever-changing phenomenon of antibiotic resistance has significantly reduced the therapeutic space to maneuver, particularly, in treating neonatal infections.

Synthesis and biological evaluation of new tetramethylpyrazine-based chalcone derivatives as potential anti-Alzheimer agents.

In the current study, a series of new ligustrazine-based chalcones was synthesized. For insertion of tetramethylpyrazine (TMP, also designated as ligustrazine) in chemical backbone of chalcone, a new ligustrazine-based aldehyde was prepared. New ketones were synthesized for inclusion of quinazolin-4-yl amino and pyrazin-2-yl amino moieties. The newly synthesized compounds were screened for acetylcholinesterase, butyrylcholinesterase, and monoamine oxidases (MAO) inhibitory activities and also for in vitro cytotoxicity on PC12 cells. The effect of these compounds against amyloid ß-induced cytotoxicity and aggregation was also investigated. The synthesized compounds effectively inhibited the related enzymes and also exhibited neuroprotective effects. Most of the compounds displayed better inhibitory potencies against Aß aggregation than reference compounds. Some compounds such as 11e and 16b showed very potent effects on multiple targets exhibiting behavior as multifunctional anti-Alzheimer agents.

Discovery of potential anticancer multi-targeted ligustrazine based cyclohexanone and oxime analogs overcoming the cancer multidrug resistance.

The drug research and development nowadays is focusing on multi-target drugs. In the treatment of cancer, therapies using drugs inhibiting one numerous targets signify a novel viewpoint. In comparison with traditional therapy, multi-targeted drugs directly aim cell subpopulations which are involved in progression of tumor. The current study comprises the synthesis of 34 novel ligustrazine-containing α, ß-unsaturated carbonyl-based compounds and oximes. The growth of 5 various cancer cell types was strongly inhibited by ligustrazine-containing oximes as revealed by biological evaluation. A strong SAR was provided by the antiproliferative activity. The mechanistic effects of most active antiproliferative compounds on tubulin polymerization, EGFR TK kinases, KAF and BRAFV600E were investigated, followed by in vitro investigation of reversal of efflux-based resistance developed by cancer cells. EGFR was strongly inhibited by two oximes 7e and 8o. Out of all linkers including positive control, 1-isopropyl-piperidin-4-one linker-bearing compounds showed best inhibition of FAK. The strongest inhibitory activity of BRAFV600E was showed by compound 5e with an IC50 of 0.7 µM. Analogs such as 5 and 7 (b,e,f) exhibited a dual role as anticancer as well as MDR reversal agents. For understanding the target protein integrations with new compounds, molecular docking studies were also carried out.

Synthesis and mechanistic studies of curcumin analog-based oximes as potential anticancer agents.

The incidence of cancer can be decreased by chemoprevention using either natural or synthetic agents. Apart from synthetic compounds, numerous natural products have exhibited promising potential to inhibit carcinogenesis in vivo. In this study, α, ß-unsaturated carbonyl-based anticancer compounds were used as starting materials to synthesize new oxime analogs. The findings from the antiproliferative assay using seven different human cancer cell lines provided a clear picture of structure-activity relationship. The oxime analogs namely 7a and 8a showed strong antiproliferative activity against the cell lines. The mechanistic effects of compounds on EGFR-TK kinases and tubulin polymerization and BRAFV600E were investigated. In addition, the efficacy of compounds in reversing the efflux-mediated resistance developed by cancer cells was also studied. The compounds 5a and 6a displayed potent activity on various targets such as BRAFV600E and EGFR-TK kinases and also exhibited strong antiproliferative activity against different cell lines hence showing potential of multifunctional anticancer agents.

Stability, Intracellular Delivery, and Release of siRNA from Chitosan Nanoparticles Using Different Cross-Linkers.

Chitosan (CS) nanoparticles have been extensively studied for siRNA delivery; however, their stability and efficacy are highly dependent on the types of cross-linker used. To address this issue, three common cross-linkers; tripolyphosphate (TPP), dextran sulphate (DS) and poly-D-glutamic acid (PGA) were used to prepare siRNA loaded CS-TPP/DS/PGA nanoparticles by ionic gelation method. The resulting nanoparticles were compared with regard to their physicochemical properties including particle size, zeta potential, morphology, binding and encapsulation efficiencies. Among all the formulations prepared with different cross linkers, CS-TPP-siRNA had the smallest particle size (ranged from 127 ± 9.7 to 455 ± 12.9 nm) with zeta potential ranged from +25.1 ± 1.5 to +39.4 ± 0.5 mV, and high entrapment (>95%) and binding efficiencies. Similarly, CS-TPP nanoparticles showed better siRNA protection during storage at 4˚C and as determined by serum protection assay. TEM micrographs revealed the assorted morphology of CS-TPP-siRNA nanoparticles in contrast to irregular morphology displayed by CS-DS-siRNA and CS-PGA-siRNA nanoparticles. All siRNA loaded CS-TPP/DS/PGA nanoparticles showed initial burst release followed by sustained release of siRNA. Moreover, all the formulations showed low and concentration-dependent cytotoxicity with human colorectal cancer cells (DLD-1), in vitro. The cellular uptake studies with CS-TPP-siRNA nanoparticles showed successful delivery of siRNA within cytoplasm of DLD-1 cells. The results demonstrate that ionically cross-linked CS-TPP nanoparticles are biocompatible non-viral gene delivery system and generate a solid ground for further optimization studies, for example with regard to steric stabilization and targeting.

Development of Chitosan Nanoparticles as a Stable Drug Delivery System for Protein/siRNA.

Chitosan nanoparticles (CS NPs) exhibit good physicochemical properties as drug delivery systems. The aim of this study is to determine the modulation of preparative parameters on the physical characteristics and colloidal stability of CS NPs. CS NPs were fabricated by ionic interaction with dextran sulphate (DS) prior to determination of their storage stability. The smallest CS NPs of 353 ± 23 nm with a surface charge of +56.2 ± 1.5 mV were produced when CS and DS were mixed at pH 4 and with a DS : CS mass ratio of 0.5 : 1. An entrapment efficiency of 98% was achieved when BSA/siRNA was loaded into the nanoparticles. The results also showed that particle size and surface charge of CS NPs were slightly changed up to 2 weeks when stored at 4°C. Greater particle size and surface charge were obtained with increasing the concentration of DS. In conclusion, NPs were sufficiently stable when kept at 4°C and able to carry and protect protein.