Overcoming colloidal nanoparticle aggregation in biological milieu for cancer therapeutic delivery: Perspectives of materials and particle design

Nanoparticles as cancer therapeutic carrier fail in clinical translation due to complex biological environments in vivo consisting of electrolytes and proteins which render nanoparticle aggregation and unable to reach action site. This review identifies the desirable characteristics of nanoparticles and their constituent materials that prevent aggregation from site of administration (oral, lung, injection) to target site. Oral nanoparticles should ideally be 75-100 nm whereas the size of pulmonary nanoparticles minimally affects their aggregation. Nanoparticles generally should carry excess negative surface charges particularly in fasting state and exert steric hindrance through surface decoration with citrate, anionic surfactants and large polymeric chains (polyethylene glycol and polyvinylpyrrolidone) to prevent aggregation. Anionic as well as cationic nanoparticles are both predisposed to protein corona formation as a function of biological protein isoelectric points. Their nanoparticulate surface composition as such should confer hydrophilicity or steric hindrance to evade protein corona formation or its formation should translate into steric hindrance or surface negative charges to prevent further aggregation. Unexpectedly, smaller and cationic nanoparticles are less prone to aggregation at cancer cell interface favoring endocytosis whereas aggregation is essential to enable nanoparticles retention and subsequent cancer cell uptake in tumor microenvironment. Present studies are largely conducted in vitro with simplified simulated biological media. Future aggregation assessment of nanoparticles in biological fluids that mimic that of patients is imperative to address conflicting materials and designs required as a function of body sites in order to realize the future clinical benefits.

Preventive mechanisms of Chinese Tibetan medicine Triphala against nonalcoholic fatty liver disease

BACKGROUND

Triphala (TLP), as a Chinese Tibetan medicine composing of Emblica officinalis, Terminalia chebula and Terminalia bellirica (1.2:1.5:1), exhibited hepatoprotective, hypolipidemic and gut microbiota modulatory effects. Nonetheless, its roles in prevention of high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) and the related mechanistic insights involving the interplay of gut microbiota and hepatic inflammation are not known.

PURPOSE

The present study seeks to determine if TLP would prevent HFD-induced NAFLD in vivo and its underlying mechanisms from the perspectives of gut microbiota, metabolites, and hepatic inflammation.

METHODS

TLP was subjected to extraction and chemo-profiling, and in vivo evaluation in HFD-fed rats on hepatic lipid and inflammation, intestinal microbiota, short-chain fatty acids (SCFAs) and permeability, and body weight and fat content profiles.

RESULTS

The TLP was primarily constituted of gallic acid, corilagin and chebulagic acid. Orally administered HFD-fed rats with TLP were characterized by the growth of Ligilactobacillus and Akkermansia, and SCFAs (acetic/propionic/butyric acid) secretion which led to increased claudin-1 and zonula occludens-1 expression that reduced the mucosal permeability to migration of lipopolysaccharides (LPS) into blood and liver. Coupling with hepatic cholesterol and triglyceride lowering actions, the TLP mitigated both inflammatory (ALT, AST, IL-1β, IL-6 and TNF-α) and pro-inflammatory (TLR4, MYD88 and NF-κB P65) activities of liver, and sequel to histopathological development of NAFLD in a dose-dependent fashion.

CONCLUSION

TLP is promisingly an effective therapy to prevent NAFLD through modulating gut microbiota, mucosal permeability and SCFAs secretion with liver fat and inflammatory responses.

Conversion of liquid chitosan-based nanoemulsions into inhalable solid microparticles: Process challenges with polysaccharide

Solid particles ≤5 μm are essential to allow lower lung deposition and macrophage phagocytosis of anti-tubercular drugs. Decorating liquid nanoemulsion of anti-tubercular drug with macrophage-specific chitosan and chitosan-folate conjugate and spray drying the nanoemulsion with lactose produced oversized solid particles due to polysaccharide binding effects. This study designed solid nanoemulsion using lactose as the primary solid carrier and explored additives and spray-drying variables to reduce the binding and particle growth effects of chitosan. Deposition of magnesium stearate on lactose negated chitosan-inducible excessive lactose-liquid nanoemulsion binding and solid particle growth. Moderating the adhesion of chitosan-decorated liquid nanoemulsion onto lactose produced smooth-surface solid microparticles (size: 5.45 ± 0.26 μm; roughness: ∼80 nm) with heterogeneous size (span: 1.87 ± 1.21) through plasticization of constituent materials of nanoemulsion and lactose involving OH/N-H, C-H, CONH and/or COO moieties. Smaller solid particles could attach onto the larger particles with minimal steric hindrance by smooth surfaces. Together with round solid particulate structures (circularity: 0.919 ± 0.002), good pulmonary inhalation beneficial for treatment of pulmonary tuberculosis as well as other diseases is conferred.

Functionalized chitosan for cancer nano drug delivery

Chitosan is a biotechnological derivative of chitin receiving a widespread pharmaceutical and biomedical applications. It can be used to encapsulate and deliver cancer therapeutics with inherent pH-dependent solubility to confer drug targeting at tumour microenvironment and anti-cancer activity synergizing cancer cytotoxic drug actions. To further reduce the off-target and by-stander adverse effects of drugs, a high targeted drug delivery efficiency at the lowest possible drug doses is clinically required. The chitosan has been functionalized with covalent conjugates or complexes and processed into nanoparticles to encapsulate and control drug release, to avoid premature drug clearance, to deliver drugs passively and actively to cancer site at tissue, cell or subcellular levels, and to promote cancer cell uptake of nanoparticles through membrane permeabilization at higher specificity and scale. Nanomedicine developed using functionalized chitosan translates to significant preclinical improvements. Future challenges related to nanotoxicity, manufacturability, selection precision of conjugates and complexes as a function of cancer omics and their biological responses from administration site to cancer target need critical assessments.

Comparison of virus-capsid mimicking biologic-shell based versus polymeric-shell nanoparticles for enhanced oral insulin delivery

Virus-capsid mimicking mucus-permeable nanoparticles are promising oral insulin carriers which surmount intestinal mucus barrier. However, the impact of different virus-capsid mimicking structure remains unexplored. In this study, utilizing biotin grafted chitosan as the main skeleton, virus-mimicking nanoparticles endowed with biologic-shell (streptavidin coverage) and polymeric-shell (hyaluronic acid/alginate coating) were designed with insulin as a model drug by self-assembly processes. It was demonstrated that biologic-shell mimicking nanoparticles exhibited a higher intestinal trans-mucus (>80%, 10 min) and transmucosal penetration efficiency (1.6-2.2-fold improvement) than polymeric-shell counterparts. Uptake mechanism studies revealed caveolae-mediated endocytosis was responsible for the absorption of biologic-shell mimicking nanoparticles whereas polymeric-shell mimicking nanoparticles were characterized by clathrin-mediated pathway with anticipated lysosomal insulin digestion. Further, in vivo hypoglycemic study indicated that the improved effect of regulating blood sugar levels was virus-capsid structure dependent out of which biologic-shell mimicking nanoparticles presented the best performance (5.1%). Although the findings of this study are encouraging, much more work is required to meet the standards of clinical translation. Taken together, we highlight the external structural dependence of virus-capsid mimicking nanoparticles on the muco-penetrating and uptake mechanism of enterocytes that in turn affecting their in vivo absorption, which should be pondered when engineering virus-mimicking nanoparticles for oral insulin delivery.

Reinvention of starch for oral drug delivery system design

Starch is a polysaccharide with varying amylose-to-amylopectin ratios as a function of its biological sources. It is characterized by low shear stress resistance, poor aqueous/organic solubility and gastrointestinal digestibility which limit its ease of processing and functionality display as an oral drug delivery vehicle. Modulation of starch composition through genetic engineering primarily alters amylose-to-amylopectin ratio. Greater molecular properties changes require chemical and enzymatic modifications of starch. Acetylation reduces water solubility and enzymatic digestibility of starch. Carboxymethylation turns starch acid-insoluble and aggregative at low pHs. The summative effects are sustaining drug release in the upper gut. Acid-insoluble carboxymethylated starch can be aminated to provide an ionic character essential for hydrogel formation which further reduces its drug release. Ionic starch can coacervate with oppositely charged starch, non-starch polyelectrolyte or drug into insoluble, controlled-release complexes. Enzymatically debranched and resistant starch has a small molecular size which confers chain aggregation into a helical hydrogel network that traps the drug molecules, protecting them from biodegradation. The modified starch has been used to modulate the intestinal/colon-specific or controlled systemic delivery of oral small molecule drugs and macromolecular therapeutics. This review highlights synthesis aspects of starch and starch derivatives, and their outcomes and challenges of applications in oral drug delivery.

Pain management in community pharmacy: a survey of pharmacy customers

Introduction

Pain is one the few sensory and emotional experiences experienced by almost all humans. When pain is uncontrolled, prolonged or disabling, people are likely to seek help from healthcare professionals1. Community pharmacies are located in the centre of communities, providing easy access to highly trained healthcare professionals, and medicines, without an appointment. Consequently, many customer interactions within pharmacies may relate to pain, however current information on the utilisation of community pharmacies for pain management and the nature of interactions is limited.

Aim

To gain a greater understanding of how pharmacy customers use community pharmacies to manage pain.

Methods

A questionnaire survey was administered to customers in 14 community pharmacies situated within the East Midlands between 7th and 26th March 2022. Pharmacy customers were approached and invited to take part if they were aged 18 years or above and had capacity. Participants were asked information about their use of community pharmacy in general, and their use of community pharmacy in relation to pain and pain medicines. Responses were recorded electronically using the Qualtrics survey platform. Descriptive statistics were derived using Microsoft Excel. Ethical approval for the study was given by the School of Pharmacy Research Ethics Committee at the University of Nottingham (ref 2017-017er).

Results

Of the pharmacy customers approached, 2798 consented to taking part in the survey (response rate = 36.2%). Approximately two-thirds of participants were female (68.7%, n=1901), and around half were aged 50 years or older (51.8%, n=1434). The most common reason for visiting the pharmacy was to collect a prescription (42.5%, n=1159), followed by purchasing a non-medicinal product (34.4%, n=937). The third most common reason for visiting the pharmacy was to purchase a medicine (19.8%, n=540). The majority of customers reported purchasing a medicine for pain from the pharmacy counter in the past (84.8%, n=2277), approximately half had used a community pharmacy to get advice about a medicine for pain (55.4%, n=1468), and slightly fewer had used a community pharmacy for advice about a painful condition (41.9%, n=1076). Of those who had sought advice for a painful condition, most customers reported this being for a new painful condition (70.5%, n=759), with a third seeking advice for pain from a long-term problem (32.5%, n=350). Fewer customers had sought advice for long-term pain which had recently become worse (17.8%, n=191).

Discussion/Conclusion

A significant proportion of pharmacy customers participating in this survey reported purchasing a pain medicine from the pharmacy counter and/or seeking advice about a pain medicine or a painful condition. These results suggest community pharmacies play an important role in the management of pain and supporting the wider NHS. Whilst survey participation was substantial, the results may not reflect the use of community pharmacy throughout the UK. Further analysis of this survey and future work will help to inform how community pharmacies can develop their role in pain management to improve care and support other parts of the health service.

References

1. Thorstensson, C.A., Gooberman-Hill, R., Adamson, J. et al. Help-seeking behaviour among people living with chronic hip or knee pain in the community. BMC Musculoskelet Disord, 2009;10(1):153.

Membrane technology for pesticide removal from aquatic environment: Status quo and way forward

The noxious side effects of pesticides on human health and environment have prompted the search of effective and reliable treatment techniques for pesticide removal. The removal of pesticides can be accomplished through physical, chemical and biologicals. Physical approaches such as filtration and adsorption are prevailing pesticide removal strategies on account of their effectiveness and ease of operation. Membrane-based filtration technology has been recognized as a promising water and wastewater treatment approach that can be used for a wide range of organic micropollutants including pesticides. Nanofiltration (NF), reverse osmosis (RO) and forward osmosis (FO) have been increasingly explored for pesticide removal from aquatic environment owing to their versatility and high treatment efficiencies. This review looks into the remedial strategies of pesticides from aqueous environment using membrane-based processes. The potentials and applications of three prevailing membrane processes, namely NF, RO and FO for the treatment of pesticide-containing wastewater are discussed in terms of the development of advanced membranes, separation mechanisms and system design. The challenges in regards to the practical implementation of membrane-based processes for pesticide remediation are identified. The corresponding research directions and way forward are highlighted. An in depth understanding of the pesticide nature, water chemistry and the pesticide-membrane interactions is the key to achieving high pesticide removal efficiency. The integration of membrane technology and conventional removal technologies represents a new dimension and the future direction for the treatment of wastewater containing recalcitrant pesticides.

Exploring Intestinal Surface Receptors in Oral Nanoinsulin Delivery

Subcutaneous and inhaled insulins are associated with needle phobia, lipohypertrophy, lipodystrophy, and cough in diabetes treatment. Oral nanoinsulin has been developed, reaping the physiologic benefits of peroral administration. This review profiles intestinal receptors exploitable in targeted delivery of oral nanoinsulin. Intestinal receptor targeting improves oral insulin bioavailability and sustains blood glucose-lowering response. Nonetheless, these studies are conducted in small animal models with no optimization of insulin dose, targeting ligand type and content, and physicochemical and molecular biologic characteristics of nanoparticles against the in vivo/clinical diabetes responses as a function of the intestinal receptor population characteristics with diabetes progression. The interactive effects between nanoinsulin and antidiabetic drugs on intestinal receptors, including their up-/downregulation, are uncertain. Sweet taste receptors upregulate SGLT-1, and both have an undefined role as new intestinal targets of nanoinsulin. Receptor targeting of oral nanoinsulin represents a viable approach that is relatively green, requiring an in-depth development of the relationship between receptors and their pathophysiological profiles with physicochemical attributes of the oral nanoinsulin. SIGNIFICANCE STATEMENT: Intestinal receptor targeting of oral nanoinsulin improves its bioavailability with sustained blood glucose-lowering response. Exploring new intestinal receptor and tailoring the design of oral nanoinsulin to the pathophysiological state of diabetic patients is imperative to raise the insulin performance to a comparable level as the injection products.

Advanced Dome cellulose/alginate/chitosan composite matrix design with gastric and intestinal co-targeting capacities

Dome matrix was designed with gastric and intestinal targeting capacities using melatonin and caffeine as model drugs, and alginate, chitosan and cellulose as composite materials. The melatonin, caffeine and intermediate hydroxypropylmethylcelluose-based dispersible modules were prepared through compaction. Caffeine piled module was capped at both ends with melatonin void modules via intermediate dispersible modules into Dome matrix. Dispersion of intermediate module detached melatonin module from Dome matrix and had it floated in stomach providing a more complete melatonin release due to favorable pH-pKa relationship of dissolution medium and drug. With reference to the caffeine module, the detachment of melatonin module facilitated its gastrointestinal transit as a reduced size matrix, with majority of caffeine delivered in colon. The dual site-targeted and -release Dome matrix is applicable as reference oral carrier for pharmaceutical, nutraceutical, functional food and veterinary medicine where a complex formulation and performancein vivoare required.

Identification of novel biomarkers in prostate cancer diagnosis and prognosis

Prostate cancer (PCa) is a common urinary malignancy. The lack of specific and sensitive biomarkers for the early diagnosis and prognosis of PCa makes it important to seek alternatives. R software was used to analyze the PCa expression profile from data sets in Gene Expression Omnibus. Core differential genes were identified by String and Cytoscape and further validated by Gene Expression Profiling Interactive Analysis (GEPIA) and The Human Protein Atlas (HPA). Gene Ontology analysis was done in the DIVID database and visualization analysis was conducted by Hiplot. Pathway enrichment was analyzed by IPA. To identify potential competitive endogenous RNAs (ceRNA) networks, the experimentally validated microRNA-target interactions database (miRTarBase), The Encyclopedia of RNA Interactomes (StarBase), lncBase, and GEPIA were used. The lncLocator was utilized to perform subcellular localization of long noncoding RNAs (lncRNAs). Both miRTarBase and StarBase were used to find the binding site of mRNAs-miRNAs and miRNAs-lncRNAs. Visualization of the ceRNA network was performed with Cytoscape. Nine genes closely related to the diagnosis and prognosis of PCa were obtained, including four identified biomarkers by HPA, CENPF, TPX2, TK1, and CCNB1, and five novel PCa biomarkers, RRM2, UBE2C, TOP2A, BIRC5, and ZWINT. Pathway analysis indicated that PCa carcinogenesis was highly correlated with liver fibrosis pathways, ILK signaling, and NRF2-mediated oxidative stress response. Two sets of ceRNA networks, BIRC5/hsa-miR-218-5p/NEAT1 and UBE2C/hsa-miR-483-3p/NEAT1 were found to be novel biomarkers for the identification of PCa. The quantitative real-time polymerase chain reaction results verified that UBE2C, BIRC5, and NEAT1 were upregulated and hsa-miR-218-5p and hsa-miR-483-3p were downregulated in human PCa cells compared with normal prostate epithelial cells. The novel identified biomarkers in this study would be valuable for the diagnosis and prognosis of PCa.

Challenges and Complications of Poly(lactic-co-glycolic acid)-Based Long-Acting Drug Product Development

Poly(lactic-co-glycolic acid) (PLGA) is one of the preferred polymeric inactive ingredients for long-acting parenteral drug products that are constituted of complex formulations. Despite over 30 years of use, there are still many challenges faced by researchers in formulation-related aspects pertaining to drug loading and release. Until now, PLGA-based complex generic drug products have not been successfully developed. The complexity in developing these generic drug products is not just due to their complex formulation, but also to the manufacturing process of the listed reference drugs that involve PLGA. The composition and product attributes of commercial PLGA formulations vary with the drugs and their intended applications. The lack of standard compendial methods for in vitro release studies hinders generic pharmaceutical companies in their efforts to develop PLGA-based complex generic drug products. In this review, we discuss the challenges faced in developing PLGA-based long-acting injectable/implantable (LAI) drug products; hurdles that are associated with drug loading and release that are dictated by the physicochemical properties of PLGA and product manufacturing processes. Approaches to overcome these challenges and hurdles are highlighted specifically with respect to drug encapsulation and release.

Chitosan oleate-tripolyphosphate complex-coated calcium alginate bead: Physicochemical aspects of concurrent core-coat formation

This study designed chitosan species-coated calcium alginate beads through concurrent core-coat formation. Chitosan oleate was synthesized by carbodiimide chemistry and characterized by ¹H NMR and FTIR techniques. Chitosan or chitosan oleate was coated onto the forming alginate or alginate/tripolyphosphate core using vibratory nozzle extrusion-microencapsulation approach, followed by calcium crosslinking. Chlorpheniramine maleate served as a model water-soluble drug. The molecular characteristics, size, shape, morphology, swelling, erosion, water uptake, drug content and drug release profiles of beads were evaluated. Discrete spherical coated beads were obtained through minimizing successive bead adhesion through an interplay of nozzle vibrational frequency and polymeric solution flow rate. The tripolyphosphate ions in the core possessed higher diffusional kinetics than alginate and were better able to attract chitosan species onto bead surfaces to facilitate alginate-chitosan coacervation. Amphiphilic chitosan oleate formed smaller aggregates than chitosan. It interacted with greater ease with core alginate and tripolyphosphate. The gain in alginate/tripolyphosphate interaction with chitosan oleate at the core-coat interface enhanced bead robustness against swelling and water uptake with drug release consequently dependent on the loss of alginate-drug interaction.

Inhalable Microparticles Embedding Calcium Phosphate Nanoparticles for Heart Targeting: The Formulation Experimental Design

Inhalation of Calcium Phosphate nanoparticles (CaPs) has recently unmasked the potential of this nanomedicine for a respiratory lung-to-heart drug delivery targeting the myocardial cells. In this work, we investigated the development of a novel highly respirable dry powder embedding crystalline CaPs. Mannitol was selected as water soluble matrix excipient for constructing respirable dry microparticles by spray drying technique. A Quality by Design approach was applied for understanding the effect of the feed composition and spraying feed rate on typical quality attributes of inhalation powders. The in vitro aerodynamic behaviour of powders was evaluated using a medium resistance device. The inner structure and morphology of generated microparticles were also studied. The 1:4 ratio of CaPs/mannitol led to the generation of hollow microparticles, with the best aerodynamic performance. After microparticle dissolution, the released nanoparticles kept their original size.

In vitro Digestion and Swelling Kinetics of Thymoquinone-Loaded Pickering Emulsions Incorporated in Alginate-Chitosan Hydrogel Beads

The present work aimed to investigate the swelling behavior, in vitro digestion, and release of a hydrophobic bioactive compound, thymoquinone (TQ), loaded in Pickering emulsion incorporated in alginate-chitosan hydrogel beads using a simulated gastrointestinal model. In this study, oil-in-water Pickering emulsions of uniform micron droplet sizes were formulated using 20% red palm olein and 0.5% (w/v) cellulose nanocrystals-soy protein isolate (CNC/SPI) complex followed by encapsulation within beads. FT-IR was used to characterize the bonding between the alginate, chitosan, and Pickering emulsion. 2% (w/v) alginate-1% (w/v) chitosan hydrogel beads were found to be spherical with higher stability against structural deformation. The alginate-chitosan beads displayed excellent stability in simulated gastric fluid (SGF) with a low water uptake of ~19%. The hydrogel beads demonstrated a high swelling degree (85%) with a superior water uptake capacity of ~593% during intestinal digestion in simulated intestinal fluid (SIF). After exposure to SIF, the microstructure transformation was observed, causing erosion and degradation of alginate/chitosan wall materials. The release profile of TQ up to 83% was achieved in intestinal digestion, and the release behavior was dominated by diffusion via the bead swelling process. These results provided useful insight into the design of food-grade colloidal delivery systems using protein-polysaccharide complex-stabilized Pickering emulsions incorporated in alginate-chitosan hydrogel beads.

Non-dispersive impact technology for powder flow characterization

This study developed a tester where the powder flow was characterized using a low sample mass (2 g) and impact instead of dispersion mechanism to mitigate test space constraint. An impact chamber was established where the test powder bed of seven lactose grades was weight-impacted to produce impact crater and ejecta, and imaged quantitatively to determine crater profiling signature (crater depth), regional topography (ejecta roughness), Otsu threshold (bed continuity) and edge segmentation (bed deformation). The Hausner ratio (HR) and Carr's index (CI) values of lactose, and their powder dispersion distance and surface area characteristics evaluated by gas-pressurized dispersibility test were examined as reference method. The crater signature profiling and regional topography were correlated to HR, CI, dispersive distance and surface area. A poorer powder flow was characterized by higher values of crater signature profiling, regional topography, HR, CI, and lower dispersive distance and surface area. The crater signature profiling and regional topography values were higher with smaller and rougher lactose particles that were cohesive. The powder impact flow is a viable non-dispersive approach to characterize powder flowability using a small sample mass and test space.

Synthesis of bio-inspired cellulose nanocrystals-soy protein isolate nanoconjugate for stabilization of oil-in-water Pickering emulsions

The development of hybrid polysaccharide-protein complexes as Pickering emulsion stabilizers has attracted increasing research interest in recent years. This work presents an eco-friendly surface modification strategy to functionalize hydrophilic cellulose nanocrystals (CNC) using hydrophobic soy protein isolate (SPI) via mussel adhesive-inspired poly (l-dopa) (PLD) to develop improved nanoconjugates as stabilizers for oil-in-water Pickering emulsion. The physicochemical properties of the CNC-PLD-SPI nanoconjugate were evaluated by solid-state ¹³C NMR, FT-IR, TGA, XRD, contact angle analysis, and TEM. The modified CNC (conjugation content of 38.22 ± 1.21%) had lowered crystallinity index, higher thermal stability, and more hydrophobic than unmodified CNC, with an average particle size of 309.9 ± 8.0 nm. Use of amphiphilic CNC-PLD-SPI nanoconjugate with greater conformational flexibility as Pickering stabilizer produced oil-in-water emulsions with greater physical stability.

Advancing skin delivery of α-tocopherol and γ-tocotrienol for dermatitis treatment via nanotechnology and microwave technology

This study investigated combination nanocarrier and microwave system for α-tocopherol and γ-tocotrienol delivery against dermatitis, without skin thinning effect of steroids. The vitamin E was formulated into water-rich/water-poor nanoemulsions, and had their droplet size, zeta potential, morphology, therapeutic content, encapsulation efficiency and release, in vitro skin therapeutics/nanoemulsion penetration, retention and permeation profiles, and in vivo pharmacodynamics characteristics examined, with skin pre-treated by precision microwave when applicable. The nanoemulsions had droplet sizes <150 nm and negative zeta potential values. The skin pre-treatment by microwave (1 mW/3985 MHz) promoted therapeutics accumulation in epidermis through enhancing nanoemulsion penetration into skin. The combination nano- and microwave technologies fluidized skin lipid and protein domains with epidermal microstructures being fluidized to a greater extent than dermis, allowing a relatively high epidermal-to-dermal nanoemulsion distribution. Microwave of lower or higher than 3985 MHz brought about lower skin therapeutics/nanoemulsion accumulation due to insufficient lipid/protein domain fluidization or microwave-skin interaction limiting at skin surfaces only. Using water-rich nanoemulsion with higher therapeutic release and skin pre-treatment with 3985 MHz microwave, dermatitis was alleviated in vivo without skin thinning of standard steroid. The use of combination microwave and nanotechnology promotes vitamin delivery and translates to positive dermatitis treatment outcome that warrants future investigation.

A review on chitosan and its development as pulmonary particulate anti-infective and anti-cancer drug carriers

Chitosan, as a biodegradable and biocompatible polymer, is characterized by anti-microbial and anti-cancer properties. It lately has received a widespread interest for use as the pulmonary particulate backbone materials of drug carrier for the treatment of infectious disease and cancer. The success of chitosan as pulmonary particulate drug carrier is a critical interplay of their mucoadhesive, permeation enhancement and site/cell-specific attributes. In the case of nanocarriers, various microencapsulation and micro-nano blending systems have been devised to equip them with an appropriate aerodynamic character to enable efficient pulmonary aerosolization and inhalation. The late COVID-19 infection is met with acute respiratory distress syndrome and cancer. Chitosan and its derivatives are found useful in combating HCoV and cancer as a function of their molecular weight, substituent type and its degree of substitution. The interest in chitosan is expected to rise in the next decade from the perspectives of drug delivery in combination with its therapeutic performance.

In Vitro Hepatic Metabolism of Curcumin Diethyl Disuccinate by Liver S9 from Different Animal Species

Liver S9 (LS9) is a nearly complete collection of all hepatic drug-metabolizing enzymes. It is a low-cost model for predicting drug metabolic activity. This study aimed to identify the suitability of using LS9 of different animal sources in drug metabolism profiling with respect to the possible translation of the in vitro outcomes to clinical studies. The in vitro hepatic metabolism of curcumin diethyl disuccinate (CDD) in LS9 of rats, dogs, monkeys, and humans was evaluated. The identity of CDD metabolites and the metabolism kinetic parameters, including degradation rate constant, in vitro/in vivo intrinsic clearance, and half-life, were determined. CDD was rapidly metabolized into monoethylsuccinyl curcumin and curcumin in LS9 of all tested species mainly by carboxylesterases (CESs), including CES1 and CES2, and butyrylcholinesterase. The in vitro intrinsic clearance of CDD was in the order of human > dog > monkey > rat, whereas that of monoethylsuccinyl curcumin in the order of dog > monkey > human > rat; this parameter was not correlated with their respective in vivo clearance, which followed the order of dog > monkey > rat > human. Therefore, in vitro drug metabolism data inferred from LS9 of nonhuman origin, especially from monkeys and dogs, cannot be used as preclinical data for human trials, as humans have a smaller liver-to-body weight ratio than monkeys, dogs, and rats. The in vivo drug metabolism is dictated by the anatomical factors of the test subject.

Design of oral intestinal-specific alginate-vitexin nanoparticulate system to modulate blood glucose level of diabetic rats

Vitexin of Ficus deltoidea exhibits intestinal α-glucosidase inhibitory and blood glucose lowering effects. This study designs oral intestinal-specific alginate nanoparticulate system of vitexin. Nanospray-dried alginate, alginate/stearic acid and alginate-C18 conjugate nanoparticles were prepared. Stearic acid was adopted to hydrophobize the matrix and minimize premature vitexin release in stomach, whereas C-18 conjugate as immobilized fatty acid to sustain hydrophobic effect and drug release. Nanoparticles were compacted with polyethylene glycol (PEG 3000, 10,000 and 20,000). The physicochemical, drug release, in vivo blood glucose lowering and intestinal vitexin content of nanoparticles and compact were determined. Hydrophobization of alginate nanoparticles promoted premature vitexin release. Compaction of nanoparticles with PEG minimized vitexin release in the stomach, with stearic acid loaded nanoparticles exhibiting a higher vitexin release in the intestine. The introduction of stearic acid reduced vitexin-alginate interaction, conferred alginate-stearic acid mismatch, and dispersive stearic acid-induced particle breakdown with intestinal vitexin release. Use of PEG 10,000 in compaction brought about PEG-nanoparticles interaction that negated initial vitexin release. The PEG dissolution in intestinal phase subsequently enabled particle breakdown and vitexin release. The PEG compacted nanoparticles exhibited oral intestinal-specific vitexin release, with positive blood glucose lowering and enhanced intestinal vitexin content in vivo.

Folate-induced nanostructural changes of oligochitosan nanoparticles and their fate of cellular internalization by melanoma

This study examined the effects of folate environment of oligochitosan nanoparticles on their cellular internalization profiles in human melanoma cells. The conjugates and nanoparticles of oligochitosan-folate, oligochitosan-carboxymethyl-5-fluorouracil, and oligochitosan-folate-carboxymethyl-5-fluorouracil were synthesized by carbodiimide chemistry and prepared by nanospray drying technique respectively. The cellular internalization profiles of oligochitosan-folate nanoparticles against the human malignant melanoma cell line (SKMEL-28) were evaluated using confocal scanning electron microscopy technique through fluorescence labelling and endocytic inhibition, as a function of nanoparticulate folate content, size, polydispersity index, zeta potential, shape, surface roughness and folate population density. The cytotoxicity and cell cycle arrest characteristics of oligochitosan-folate-carboxymethyl-5-fluorouracil nanoparticles, prepared with an optimal folate content that promoted cellular internalization, were evaluated against the oligochitosan-folate and oligochitosan-carboxymethyl-5-fluorouracil conjugate nanoparticles. The oligochitosan-folate conjugate nanoparticles were endocytosed by melanoma cells via caveolae- and lipid raft-mediated endocytic pathways following them binding to the cell surface folate receptor. Nanoparticles that were larger and with higher folic acid contents and zeta potentials exhibited a higher degree of cellular internalization. Excessive conjugation of nanoparticles with folate resulted in a high nanoparticulate density of folate which hindered nanoparticles-cell interaction via folate receptor binding and reduced cellular internalization of nanoparticles. Conjugating oligochitosan with 20 %w/w folate was favorable for cellular uptake as supported by in silico models. Conjugating of oligochitosan nanoparticles with carboxymethyl-5-fluorouracil and 20 %w/w of folate promoted nanoparticles-folate receptor binding, cellular internalization and cancer cell death via cell cycle arrest at S phase at a lower drug dose than oligochitosan-carboxymethyl-5-fluorouracil conjugate nanoparticles and neat carboxymethyl-5-fluorouracil.

Design of multi-particulate "Dome matrix" with sustained-release melatonin and delayed-release caffeine for jet lag treatment

Multi-particulate Dome matrix with sustained-release melatonin and delayed-release caffeine was designed to restore jet lag sleep-wake cycle. The polymeric pellets were produced using extrusion-spheronization technique and fluid-bed coated when applicable. The compact and Dome module were produced by compressing pellets with cushioning agent. Dome matrix was assembly of modules with pre-determined compact formulation and drug release characteristics. The physicochemical and in vivo pharmacokinetics of delivery systems were examined. Melatonin loaded alginate/chitosan-less matrix exhibited full drug release within 8 h gastrointestinal transit with low viscosity hydroxypropymethylcellulose as cushioning agent. The cushioning agent reduced burst drug release and omission of alginate-chitosan enabled full drug release. Delayed-release alginate-chitosan caffeine matrix was not attainable through polymer coating due to premature coat detachment. Admixing of cushioning agent high viscosity hydroxypropylmethylcellulose and high viscosity ethylcellulose (9:1 wt ratio) with coat-free caffeine loaded particulates introduced delayed-release response via hydroxypropylmethylcellulose swelled in early dissolution phase and ethylcellulose sustained matrix hydrophobicity at prolonged phase. The caffeine was released substantially in colonic fluid in response to matrix polymers being degraded by rat colonic content. Dome matrix with dual drug release kinetics and modulated pharmacokinetics is produced to introduce melatonin-induced sleep phase then caffeine-stimulated wake phase.

High-fidelity simulation training programme for final-year medical students: implications from the perceived learning outcomes

We designed a session of high-fidelity simulation training course for final-year medical students in their emergency medicine specialty clerkship. This was a new initiative with clearly defined learning outcomes. We aimed to evaluate the learning outcomes. Students completed an evaluation form at the end of the session focusing on their perceived learning outcomes. Thematic analysis was conducted for data processing. We collected responses from 149 students. In addition to the intended outcomes of the course, students gained unexpected learning outcomes from the training and some of them matched a few identified learning gaps between undergraduate medical education and their subsequent transition to early clinical practice that have been described in the literature. High-fidelity simulation training in medical school could be an effective tool to address some of the identified gaps in the transition between undergraduate medical education and postgraduate practice.

In vitro evaluation of the inhalable quercetin loaded nanoemulsion for pulmonary delivery

Bioavailability of quercetin, a flavonoid potentially known to combat cancer, is challenging due to hydrophobic nature. Oil-in-water (O/W) nanoemulsion system could be used as nanocarrier for quercertin to be delivered to lung via pulmonary delivery. The novelty of this nanoformulation was introduced by using palm oil ester/ricinoleic acid as oil phase which formed spherical shape nanoemulsion as measured by transmission electron microscopy and Zetasizer analyses. High energy emulsification method and D-optimal mixture design were used to optimize the composition towards the volume median diameter. The droplet size, polydispersity index, and zeta potential of the optimized formulation were 131.4 nm, 0.257, and 51.1 mV, respectively. The formulation exhibited high drug entrapment efficiency and good stability against phase separation and storage at temperature 4 °C for 3 months. It was discovered that the system had an acceptable median mass aerodynamic diameter (3.09 ± 0.05 μm) and geometric standard deviation (1.77 ± 0.03) with high fine particle fraction (90.52 ± 0.10%), percent dispersed (83.12 ± 1.29%), and percent inhaled (81.26 ± 1.28%) for deposition in deep lung. The in vitro release study demonstrated that the sustained release pattern of quercetin from naneomulsion formulation up to 48 h of about 26.75% release and it was in adherence to Korsmeyer's Peppas mechanism. The cytotoxicity study demonstrated that the optimized nanoemulsion can potentially induce cyctotoxicity towards A549 lung cancer cells without affecting the normal cells. These results of the study suggest that nanoemulsion is a potential carrier system for pulmonary delivery of molecules with low water solubility like quercetin.

A revisit to the effects of zinc salt on skin burn wound healing to reflect the risks in current pharmaceutical care

The lower limit of soluble zinc content that can possibly be applied onto a wounded skin as a healing promoter was not known. This study examined skin wound healing process of rats inflicted by partial thickness thermal burn wound as a function of applied soluble zinc contents (0.1 ml of zinc chloride solution 0.01% (w/w) or 5.0% (w/w)). The size, surface morphology and histological profiles of wound beds of untreated rats and those treated with zinc chloride solutions were characterized. A soluble zinc content as low as 10.5 μg/cm² of skin negated skin wound healing when compared to the untreated rats. This was alarming as the commercial products currently in the market are formulated with a high level of zinc content. Albeit the zinc salt employed was water-insoluble, a minute fraction of soluble zinc might be available to the treatment sites. This could be partially responsible for the late adverse effects such as pruritis and inflammation reported with calamine/diphenhydramine lotion, medicated shampoo, Olay Complete defense moisturizing lotion and Zineryt^® topical solution. The skin irritation was likely a resultant oxidative stress action of soluble zinc, where a small fraction could be adequate to negate the skin homeostasis.[Figure: see text]Key messagesZinc is essentially a cofactor for skin collagen formation.Soluble zinc content as low as 10.5 μg/cm² of skin irritates skin and negates burn wound healing.Skin irritation of commercial products relates to minute soluble zinc content availability.

In Vitro Drug Dissolution/Permeation Testing of Nanocarriers for Skin Application: a Comprehensive Review

This review highlights in vitro drug dissolution/permeation methods available for topical and transdermal nanocarriers that have been designed to modulate the propensity of drug release, drug penetration into skin, and permeation into systemic circulation. Presently, a few of USFDA-approved in vitro dissolution/permeation methods are available for skin product testing with no specific application to nanocarriers. Researchers are largely utilizing the in-house dissolution/permeation testing methods of nanocarriers. These drug release and permeation methods are pending to be standardized. Their biorelevance with reference to in vivo plasma concentration-time profiles requires further exploration to enable translation of in vitro data for in vivo or clinical performance prediction.

Critical physicochemical attributes of chitosan nanoparticles admixed lactose-PEG 3000 microparticles in pulmonary inhalation

Chitosan nanoparticles are exhalation prone and agglomerative to pulmonary inhalation. Blending nanoparticles with lactose microparticles (∼5 µm) could mutually reduce their agglomeration through surface adsorption phenomenon. The chitosan nanoparticles of varying size, size distribution, zeta potential, crystallinity, shape and surface roughness were prepared by spray drying technique as a function of chitosan, surfactant and processing conditions. Lactose-polyethylene glycol 3000 (PEG3000) microparticles were similarly prepared. The chitosan nanoparticles, physically blended with fine lactose-PEG3000 microparticles, exhibited a comparable inhalation performance with the commercial dry powder inhaler products (fine particle fraction between 20% and 30%). Cascade impactor analysis indicated that the aerosolization and inhalation performance of chitosan nanoparticles was promoted by their higher zeta potential and circularity, and larger size attributes of which led to reduced inter-nanoparticulate aggregation and favored nanoparticles interacting with lactose-PEG3000 micropaticles that aided their delivery into deep and peripheral lungs.

Depression and anxiety among university students in Hong Kong

INTRODUCTION

Entry into tertiary education is a critical juncture where adolescents proceed to adulthood. This study aimed to determine the prevalence of depression and anxiety, and factors associated with such symptoms, among university undergraduate students in Hong Kong.

METHODS

A cross-sectional questionnaire study was employed. A total of 1200 undergraduate students from eight University Grants Committee-funded universities were invited to complete three sets of questionnaires, including the 9-item patient health questionnaire for screening of depressive symptoms, the 7-item generalised anxiety disorder scale for screening of anxiety symptoms, and a socio-demographic questionnaire.

RESULTS

Among the valid responses (n=1119) analysed, 767 (68.5%) respondents indicated mild to severe depressive symptoms, which were associated with mild to severe anxiety symptoms. Several lifestyle and psychosocial variables, including regular exercise, self-confidence, satisfaction with academic performance, and optimism towards the future were inversely related with mild to severe depressive symptoms. A total of 599 (54.4%) respondents indicated mild to severe anxiety symptoms, which were associated with level of academic difficulty. Satisfaction with friendship, sleep quality, and self-confidence were inversely associated with mild to severe anxiety symptoms.

CONCLUSION

More than 50% of respondents expressed some degree of depressive and anxiety symptoms (68.5% and 54.4%, respectively). Approximately 9% of respondents exhibited moderately severe to severe depressive symptoms; 5.8% exhibited severe anxiety symptoms. Respondents reporting regular exercise, higher self-confidence, and better satisfaction with both friendship and academic performance had fewer depressive and anxiety symptoms.

Water transport properties of boron nitride nanosheets mixed matrix membranes for humic acid removal

Ultrafiltration grade polysulfone-based mixed matrix membranes (MMMs) incorporated with two-dimensional boron nitride nanosheet (BNNS) was prepared via phase inversion method. The amount of BN incorporated was varied and the influence on membrane morphology, contact angle, surface charge, as well as water permeability and humic acid rejection were investigated. Results revealed that the addition of BN to the membrane matrix resulted in profound increase in water permeability (almost tripled to that of neat PSf) and humic acid rejection due to the increase in pore size and surface negative charge. Beyond the morphological changes imparted by the inclusion of BNNS, we postulated that the presence of BNNS within the membrane matrix also contribute to the enhancement in flux and rejection based on surface-slip and selective interlayer transport. Despite the favourable augmentation of water transport and filtration performance, the MMMs suffered with fouling problem due to the entrapment of foulant within the enlarged pores and the membrane valleys. Its inherent adsorptive character could be a disadvantage when utilized as membrane filler.

Polyethylene glycol-coated porous magnetic nanoparticles for targeted delivery of chemotherapeutics under magnetic hyperthermia condition

PURPOSE

Although magnetite nanoparticles (MNPs) are promising agents for hyperthermia therapy, insufficient drug encapsulation efficacies inhibit their application as nanocarriers in the targeted drug delivery systems. In this study, porous magnetite nanoparticles (PMNPs) were synthesized and coated with a thermosensitive polymeric shell to obtain a synergistic effect of hyperthermia and chemotherapy.

MATERIALS AND METHODS

PMNPs were produced using cetyltrimethyl ammonium bromide template and then coated by a polyethylene glycol layer with molecular weight of 1500 Da (PEG1500) and phase transition temperature of 48 ± 2 °C to endow a thermosensitive behavior. The profile of drug release from the nanostructure was studied at various hyperthermia conditions generated by waterbath, magnetic resonance-guided focused ultrasound (MRgFUS), and alternating magnetic field (AMF). The in vitro cytotoxicity and hyperthermia efficacy of the doxorubicin-loaded nanoparticles (DOX-PEG1500-PMNPs) were assessed using human lung adenocarcinoma (A549) cells.

RESULTS

Heat treatment of DOX-PEG1500-PMNPs containing 235 ± 26 mg·g^-1 DOX at 48 °C by waterbath, MRgFUS, and AMF, respectively led to 71 ± 4%, 48 ± 3%, and 74 ± 5% drug release. Hyperthermia treatment of the A549 cells using DOX-PEG1500-PMNPs led to 77% decrease in the cell viability due to the synergistic effects of magnetic hyperthermia and chemotherapy.

CONCLUSION

The large pores generated in the PMNPs structure could provide a sufficient space for encapsulation of the chemotherapeutics as well as fast drug encapsulation and release kinetics, which together with thermosensitive characteristics of the PEG1500 shell, make DOX-PEG1500-PMNPs promising adjuvants to the magnetic hyperthermia modality.

Development of resistant corn starch for use as an oral colon-specific nanoparticulate drug carrier

Starch is constituted of amylose and amylopectin. Debranching of amylopectin converts it into amylose thereby producing resistant starch which is known to be less digestible by the amylase. This study designed resistant starch using acid hydrolysis and heat-moisture treatment methods with native corn starch as the starting material. Both native and processed starches were subjected to Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry and molecular weight analysis. They were nanospray-dried into nanoparticles with 5-fluorouracil as the drug of interest for colon cancer treatment. These nanoparticles were subjected to size, zeta potential, morphology, drug content and in vitro drug release analysis. Heat-moisture treatment of native corn starch enabled the formation of resistant starch through amylopectin debranching and molecular weight reduction thereby enhancing hydrogen bonding between the starch molecules at the amorphous phase and gelatinization capacity. The nanoparticles prepared from resistant starch demonstrated similar drug release as those of native starch in spite of the resistant starch had a lower molecular weight. The resistant starch is envisaged to be resistant to the digestive action of amylase in intestinal tract without the formed nanoparticles exhibiting excessively fast drug release in comparison to native starch. With reduced branching, it represents an ideal precursor for targeting ligand conjugation in design of oral colon-specific nanoparticulate drug carrier.