Microparticles, microcapsules and microspheres: A review of recent developments and prospects for oral delivery of insulin

Insulin Delivery to the Brain via the Nasal Route: Unraveling the Potential for Alzheimer's Disease Therapy

This comprehensive review delves into the potential of intranasal insulin delivery for managing Alzheimer's Disease (AD) while exploring the connection between AD and diabetes mellitus (DM). Both conditions share features of insulin signalling dysregulation and oxidative stress that accelerate inflammatory response. Given the physiological barriers to brain drug delivery, including the blood-brain barrier, intranasal administration emerges as a non-invasive alternative. Notably, intranasal insulin has shown neuroprotective effects, impacting Aβ clearance, tau phosphorylation, and synaptic plasticity. In preclinical studies and clinical trials, intranasally administered insulin achieved rapid and extensive distribution throughout the brain, with optimal formulations exhibiting minimal systemic circulation. The detailed mechanism of insulin transport through the nose-to-brain pathway is elucidated in the review, emphasizing the role of olfactory and trigeminal nerves. Despite promising prospects, challenges in delivering protein drugs from the nasal cavity to the brain remain, including enzymes, tight junctions, mucociliary clearance, and precise drug deposition, which hinder its translation to clinical settings. The review encompasses a discussion of the strategies to enhance the intranasal delivery of therapeutic proteins, such as tight junction modulators, cell-penetrating peptides, and nano-drug carrier systems. Moreover, successful translation of nose-to-brain drug delivery necessitates a holistic understanding of drug transport mechanisms, brain anatomy, and nasal formulation optimization. To date, no intranasal insulin formulation has received regulatory approval for AD treatment. Future research should address challenges related to drug absorption, nasal deposition, and the long-term effects of intranasal insulin. In this context, the evaluation of administration devices for nose-to-brain drug delivery becomes crucial in ensuring precise drug deposition patterns and enhancing bioavailability.

High-yield fabrication of monodisperse multilayer nanofibrous microparticles for advanced oral drug delivery applications

Recent advances in the use of nano- and microparticles in drug delivery, cell therapy, and tissue engineering have led to increasing attention towards nanostructured microparticulate formulations for maximum benefit from both nano- and micron sized features. Scalable manufacturing of monodisperse nanostructured microparticles with tunable size, shape, content, and release rate remains a big challenge. Current technology, mainly comprises complex multi-step chemical procedures with limited control over these aspects. Here, we demonstrate a novel technique for high-yield fabrication of monodisperse monolayer and multilayer nanofibrous microparticles (MoNami and MuNaMi respectively). The fabrication procedure includes sequential electrospinning followed by micro-cutting at room temperature and transfer of particles for collection. The big advantage of the introduced technique is the potential to apply several polymer-drug combinations forming multilayer microparticles enjoying extracellular matrix (ECM)-mimicking architecture with tunable release profile. We demonstrate the fabrication and study the factors affecting the final three-dimensional structure. A model drug is encapsulated into a three-layer sheet (PLGA-pullulan-PLGA), and we demonstrate how the release profile changes from burst to sustain by simply cutting particles out of the electrospun sheet. We believe our fabrication method offers a unique and facile platform for realizing advanced microparticles for oral drug delivery applications.

Incorporation of Finasteride-Loaded Microspheres into Personalized Microneedle for Sustained Transdermal Delivery

Although finasteride (FNS) tablets are considered the most effective drug for the treatment of androgenetic alopecia (AGA), their clinical applications are limited due to the associated side effects including decreased libido, breast enlargement, and liver dysfunction. In this study, we have developed a personalized microneedle (PMN) with a double-layer structure that incorporates FNS-loaded microspheres (MPs) to accommodate irregular skin surfaces. This design enables the sustained release of FNS, thereby reducing potential side effects. The needle body was synthesized with high-strength hyaluronic acid (HA) as the base material substrate. The backing layer utilized methacrylate gelatin (GelMA) with specific toughness, enabling PMN to penetrate the skin while adapting to various skin environments. The length of PMN needles (10 × 10) was approximately 600 μm, with the bottom of the needles measuring about 330 μm × 330 μm. The distance between adjacent tips was around 600 μm, allowing the drug to penetrate the stratum corneum of the skin. The results of the drug release investigation indicated the sustained and regulated release of FNS from PMN, as compared to that of pure FNS and FNS-MPs. Further, the cytotoxicity assay demonstrates that PMS displays good cytocompatibility. Altogether, this mode of administration has immense potential for the development of delivery of other drugs, as well as in the medical field.

Current research status and development prospects of embolic microspheres containing biological macromolecules and others

Transcatheter arterial embolization (TACE) has been used in the treatment of malignant tumors, sudden hemorrhage, uterine fibroids, and other diseases, and with advances in imaging techniques and devices, materials science, and drug release technology, more and more embolic agents that are drug-carrying, self-imaging, or have multiple functions are being developed. Microspheres provide safer and more effective therapeutic results as embolic agents, with their unique spherical appearance and good embolic properties. Embolic microspheres are the key to arterial embolization, blocking blood flow and nutrient supply to the tumor target. This review summarizes some of the currently published embolic microspheres, classifies embolic microspheres according to matrix, and summarizes the characteristics of the microsphere materials, the current status of research, directions, and the value of existing and potential applications. It provides a direction to promote the development of embolic microspheres towards multifunctionalization, and provides a reference to promote the research and application of embolic microspheres in the treatment of tumors.

Molecular Engineering of Electrosprayed Hydrogel Microspheres to Achieve Synergistic Anti-Tumor Chemo-Immunotherapy with ACEA Cargo

Molecular engineering of drug delivering platforms to provide collaborative biological effects with loaded drugs is of great medical significance. Herein, cannabinoid receptor 1 (CB1)- and reactive oxygen species (ROS)-targeting electrosprayed microspheres (MSs) are fabricated by loading with the CB1 agonist arachidonoyl 2'-chloroethylamide (ACEA) and producing ROS in a photoresponsive manner. The synergistic anti-tumor effects of ACEA and ROS released from the MSs are assessed. ACEA inhibits epidermal growth factor receptor signaling and altered tumor microenvironment (TME) by activating CB1 to induce tumor cell death. The MSs are composed of glycidyl methacrylate-conjugated xanthan gum (XGMA) and Fe3+, which form dual molecular networks based on a Fe3+-(COO-)3 network and a C═C addition reaction network. Interestingly, the Fe3+-(COO-)3 network can be disassembled instantly under the conditions of lactate sodium and ultraviolet exposure, and the disassembly is accompanied by massive ROS production, which directly injures tumor cells. Meanwhile, the transition of dual networks to a single network boosts the ACEA release. Together, the activities of the ACEA and MSs promote immunogenic tumor cell death and create a tumor-suppressive TME by increasing M1-like tumor-associated macrophages and CD8+ T cells. In summation, this study demonstrates strong prospects of improving anti-tumor effects of drug delivering platforms through molecular design.

An overview of in vitro and in vivo techniques for characterization of intranasal protein and peptide formulations for brain targeting

The surge in neurological disorders necessitates innovative strategies for delivering active pharmaceutical ingredients to the brain. The non-invasive intranasal route has emerged as a promising approach to optimize drug delivery to the central nervous system by circumventing the blood-brain barrier. While the intranasal approach offers numerous advantages, the lack of a standardized protocol for drug testing poses challenges to both in vitro and in vivo studies, limiting the accurate interpretation of nasal drug delivery and pharmacokinetic data. This review explores the in vitro experimental assays employed by the pharmaceutical industry to test intranasal formulation. The focus lies on understanding the diverse techniques used to characterize the intranasal delivery of drugs targeting the brain. Parameters such as drug release, droplet size measurement, plume geometry, deposition in the nasal cavity, aerodynamic performance and mucoadhesiveness are scrutinized for their role in evaluating the performance of nasal drug products. The review further discusses the methodology for in vivo characterization in detail, which is essential in evaluating and refining drug efficacy through the nose-to-brain pathway. Animal models are indispensable for pre-clinical drug testing, offering valuable insights into absorption efficacy and potential variables affecting formulation safety. The insights presented aim to guide future research in intranasal drug delivery for neurological disorders, ensuring more accurate predictions of therapeutic efficacy in clinical contexts.

Recent developments in the fabrication of food microparticles and nanoparticles using microfluidic systems

Microfluidics is revolutionizing the production of microparticles and nanoparticles, offering precise control over dimensions and internal structure. This technology facilitates the creation of colloidal delivery systems capable of encapsulating and releasing nutraceuticals. Nutraceuticals, often derived from food-grade ingredients, can be used for developing functional foods. This review focuses on the principles and applications of microfluidic systems in crafting colloidal delivery systems for nutraceuticals. It explores the foundational principles behind the development of microfluidic devices for nutraceutical encapsulation and delivery. Additionally, it examines the prospects and challenges with using microfluidics for functional food development. Microfluidic systems can be employed to form emulsions, liposomes, microgels and microspheres, by manipulating minute volumes of fluids flowing within microchannels. This versatility can enhance the dispersibility, stability, and bioavailability of nutraceuticals. However, challenges as scaling up production, fabrication complexity, and microchannel clogging hinder the widespread application of microfluidic technologies. In conclusion, this review highlights the potential role of microfluidics in design and fabrication of nutraceutical delivery systems. At present, this technology is most suitable for exploring the role of specific delivery system features (such as particle size, composition and morphology) on the stability and bioavailability of nutraceuticals, rather than for large-scale production of nutraceutical delivery systems.

Preparation, characterization and in vitro evaluation of insulin-PHBV nanoparticles / alginate hydrogel composite system for prolonged delivery of insulin

PURPOSE

In the present study, biodegradable poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanoparticles (NPs) containing insulin were loaded in sodium alginate/jeffamine (ALG/jeff) hydrogel for prolonged delivery of insulin. The main aim of this work was to fabricate an efficient insulin delivery system to improve patient adherence by decreasing the repetition of injections.

METHODS

Swelling and morphological properties and crosslinking efficiency of ALG/jeff hydrogel were assessed. The composite hydrogel was prepared by adding PHBV NPs to ALG/jeff hydrogel concurrently with crosslinking process. The morphology and loading capacity of composite hydrogel were analyzed.

RESULTS

Circular dichroism measurement demonstrated that insulin remains stable following fabrication process. The release profile exhibited 54.6% insulin release from composite hydrogel within 31 days with minor initial burst release equated to nanoparticles and hydrogels. MTT cell viability analysis was performed by applying L-929 cell line and no cytotoxic effect was observed.

CONCLUSIONS

Favorable results clearly introduced fabricated composite hydrogel as an excellent candidate for drug delivery systems and also paves the route for prolonged delivery systems of other proteins.

A review on oral novel delivery systems of insulin through the novel delivery system formulations: A review

Parenteral administration of insulin remains the most common route of administration, causing local hypertrophy at the injection sites because of multiple daily injections. Because of this, there is an interest and effort in oral insulin administration that is convenient and mimics the physiology of endogenous insulin secreted in the liver. However, oral insulin encountered different challenges due to abundant enzyme degradation, the presence of a mucus layer, and the underlying intestinal epithelial membrane barrier in the gastrointestinal tract. This narrative review reviewed the literature dealing with novel oral insulin delivery approaches. Various pieces of literature were searched, filtered, and reviewed from different sources, and the information obtained was organized, formulated, and finalized. Oral insulin has been formulated and extensively studied in various novel delivery approaches, such as nanoparticles, microspheres, mucoadhesive patches, encapsulations, hydrogels, ionic liquids, liposomes, and complexation. The efficiency of these formulations demonstrated improved efficiency and potency compared to free oral insulin delivery, but none of them have greater or equivalent potency to subcutaneous insulin. Future studies regarding dose-dependent therapeutic efficacy and the development of new novel formulations to produce comparable oral insulin to subcutaneous insulin are warranted to further support the suitability of the current platform for oral insulin delivery.

Investigating the Impact of Network Functionalization on Protein Adsorption to Polymer Nanogels

This study explores the impact of network functionalization and chemical composition on the pH-responsive behavior of polymer nanogels and their adsorption of proteins. Using a thermodynamic theory informed by a molecular model, this work evaluates the interactions of three proteins with varying isoelectric points (insulin, myoglobin, and cytochrome c) and pH-responsive nanogels based on methacrylic acid or allylamine motifs. Three different functionalization strategies are considered, with pH-responsive segments distributed randomly, at the center, or on the surface of the polymer network. Our results show that the spatial distribution of functional units affects both the nanogels' mechanical response to pH changes and the level and localization of adsorbed proteins. The dependence of protein adsorption on the salt concentration is also investigated, with the conclusion that it is best to encapsulate proteins at low salt concentrations and aim for release at high salt concentrations. These results provide valuable information for the design of pH-responsive nanogels as vehicles for protein encapsulation, transport, and administration.

Multiple Natural Polymers in Drug and Gene Delivery Systems

Natural polymers are organic compounds produced by living organisms. In nature, they exist in three main forms, including proteins, polysaccharides, and nucleic acids. In recent years, with the continuous research on drug and gene delivery systems, scholars have found that natural polymers have promising applications in drug and gene delivery systems due to their excellent properties such as biocompatibility, biodegradability, low immunogenicity, and easy modification. However, since the structure, physicochemical properties, pharmacological properties and biological characteristics of biopolymer molecules have not yet been entirely understood, further studies are required before large-scale clinical application. This review focuses on recent advances in the representative natural polymers such as proteins (albumin, collagen, elastin), polysaccharides (chitosan, alginate, cellulose) and nucleic acids. We introduce the characteristics of various types of natural polymers, and further outline the characterization methods and delivery forms of these natural polymers. Finally, we discuss possible challenges for natural polymers in subsequent experimental studies and clinical applications. It provides an important strategy for the clinical application of natural polymers in drug and gene delivery systems.

Novel Approaches for the Management of Type 2 Diabetes Mellitus: An Update

Diabetes mellitus is an irreversible, chronic metabolic disorder indicated by hyperglycemia. It is now considered a worldwide pandemic. T2DM, a spectrum of diseases initially caused by tissue insulin resistance and slowly developing to a state characterized by absolute loss of secretory action of the β cells of the pancreas, is thought to be caused by reduced insulin secretion, resistance to tissue activities of insulin, or a combination of both. Insulin secretagogues, biguanides, insulin sensitizers, alpha-glucosidase inhibitors, incretin mimetics, amylin antagonists, and sodium-glucose co-transporter-2 (SGLT2) inhibitors are the main medications used to treat T2DM. Several of these medication's traditional dosage forms have some disadvantages, including frequent dosing, a brief half-life, and limited absorption. Hence, attempts have been made to develop new drug delivery systems for oral antidiabetics to ameliorate the difficulties associated with conventional dosage forms. In comparison to traditional treatments, this review examines the utilization of various innovative therapies (such as microparticles, nanoparticles, liposomes, niosomes, phytosomes, and transdermal drug delivery systems) to improve the distribution of various oral hypoglycemic medications. In this review, we have also discussed some new promising candidates that have been approved recently by the US Food and Drug Administration for the treatment of T2DM, like semaglutide, tirzepatide, and ertugliflozin. They are used as a single therapy and also as combination therapy with drugs like metformin and sitagliptin.

Construction and functional evaluation of oral long-acting insulin hydrogel microparticles based on physical and chemical double crosslinking

The objective of this study was to enhance the convenience and effectiveness of diabetes treatment by developing hydrogel microparticles as an oral insulin delivery system, aiming to reduce the necessity for frequent treatments. The hydrogel microparticles were prepared with polysaccharides through a combination of physical and chemical crosslinking method, they achieved good results in insulin loading efficiency (70 %), insulin release efficiency (98 %) and sustained release time (>20 h). The effective transmembrane transport was validated using an intestinal epithelial cell model, which demonstrated a continuous hypoglycemic effect lasting from 6 to 26 h in a type 2 diabetes mouse model. Additionally, the relative bioavailability of insulin reached 30.14 ± 2.62 %, representing a significant breakthrough in the field of oral insulin delivery carriers. Furthermore, oral insulin hydrogel exhibited a substantial improvement in insulin resistance, organ damage, and diabetes-related complications stemming from hyperglycemia. These compelling findings underscore the potential of hydrogel microparticles as a cost-effective and valuable strategy for oral drug delivery in diabetes treatment.

Image Synthesis and Modified BlendMask Instance Segmentation for Automated Nanoparticle Phenotyping

Automated nanoparticle phenotyping is a critical aspect of high-throughput drug research, which requires analyzing nanoparticle size, shape, and surface topography from microscopy images. To automate this process, we present an instance segmentation pipeline that partitions individual nanoparticles on microscopy images. Our pipeline makes two key contributions. Firstly, we synthesize diverse and approximately realistic nanoparticle images to improve robust learning. Secondly, we improve the BlendMask model to segment tiny, overlapping, or sparse particle images. Specifically, we propose a parameterized approach for generating novel pairs of single particles and their masks, encouraging greater diversity in the training data. To synthesize more realistic particle images, we explore three particle placement rules and an image selection criterion. The improved one-stage instance segmentation network extracts distinctive features of nanoparticles and their context at both local and global levels, which addresses the data challenges associated with tiny, overlapping, or sparse nanoparticles. Extensive experiments demonstrate the effectiveness of our pipeline for automating nanoparticle partitioning and phenotyping in drug research using microscopy images.

Enhancing Anticancer Efficacy of Formononetin Microspheres via Microfluidic Fabrication

Formononetin is a flavonoid compound with anti-tumor and anti-inflammatory properties. However, its low solubility limits its clinical use. We employed microfluidic technology to prepare formononetin-loaded PLGA-PEGDA microspheres (Degradable polymer PLGA, Crosslinking agent PEGDA), which can encapsulate and release drugs in a controlled manner. We optimized and characterized the microspheres, and evaluated their antitumor effects. The microspheres had uniform size, high drug loading efficiency, high encapsulation efficiency, and stable release for 35 days. They also inhibited the proliferation, migration, and apoptosis. The antitumor mechanism involved the induction of reactive oxygen species and modulation of Bcl-2 family proteins. These findings suggested that formononetin-loaded PLGA-PEGDA microspheres, created using microfluidic technology, could be a novel drug delivery system that can overcome the limitations of formononetin and enhance its antitumor activity.

Nanoparticle-Based Approaches for Treatment of Hematological Malignancies: a Comprehensive Review

Blood cancer, also known as hematological malignancy, is one of the devastating types of cancer that has significantly paved its mortality mark globally. It persists as an extremely deadly cancer type and needs utmost attention owing to its negligible overall survival rate. Major challenges in the treatment of blood cancer include difficulties in early diagnosis, as well as severe side effects resulting from chemotherapy. In addition, immunotherapies and targeted therapies can be prohibitively expensive. Over the past two decades, scientists have devised a few nanoparticle-based drug delivery systems aimed at overcoming this challenge. These therapeutic strategies are engineered to augment the cellular uptake, pharmacokinetics, and effectiveness of anticancer drugs. However, there are still numerous types of nanoparticles that could potentially improve the efficacy of blood cancer treatment, while also reducing treatment costs and mitigating drug-related side effects. To the best of our knowledge, there has been limited reviews published on the use of nano-based drug delivery systems for the treatment of hematological malignancies. Therefore, we have made a concerted effort to provide a comprehensive review that draws upon recent literature and patents, with a focus on the most promising results regarding the use of nanoparticle-based approaches for the treatment of hematological malignancies. All these crucial points covered under a common title would significantly help researchers and scientists working in the area.

Microparticles and nanoparticles-based approaches to improve oral treatment of Helicobacter pylori infection

Helicobacter pylori is a gram-negative, spiral-shaped, flagellated bacterium that colonizes the stomach of half the world's population. Helicobacter pylori infection causes pathologies of varying severity. Standard oral therapy fails in 15-20% since the barriers of the oral route decrease the bioavailability of antibiotics and the intrinsic factors of bacteria increase the rates of resistance. Nanoparticles and microparticles are promising strategies for drug delivery into the gastric mucosa and targeting H. pylori. The variety of building blocks creates systems with distinct colloidal, surface, and biological properties. These features improve drug-pathogen interactions, eliminate drug depletion and overuse, and enable the association of multiple actives combating H. pylori on several fronts. Nanoparticles and microparticles are successfully used to overcome the barriers of the oral route, physicochemical inconveniences, and lack of selectivity of current therapy. They have proven efficient in employing promising anti-H. pylori compounds whose limitation is oral route instability, such as some antibiotics and natural products. However, the current challenge is the applicability of these strategies in clinical practice. For this reason, strategies employing a rational design are necessary, including in the development of nano- and microsystems for the oral route.

Prolonged Anesthesia Effects of Locally Administered Ropivacaine via Electrospun Poly(caprolactone) Fibrous Membranes

Prolonged analgesia is important to safeguard the patient's comfort and safety during and after surgery in clinical practice. To meet the demand for prolonged analgesia, medical professionals often resort to increasing drug frequency, which may lead to poor patient compliance and serious complications due to drug overdose. Therefore, it is of great interest to develop controlled-release drug delivery systems for local anesthetics, enabling slow and controlled drug release to prolong the analgesic effect and minimize systemic toxicity. In this study, we utilized an electrospinning technique to fabricate nonwoven poly(caprolactone) (PCL) fibrous membranes loaded with Ropivacaine and performed proof-of-principle experiments on both in vitro drug release tests and in vivo animal tests, to further prolong the analgesic effect of Ropivacaine and improve postoperative local pain management and chronic pain treatment. Material characterization and in vitro drug release studies confirmed the feasibility of the Ropivacaine-loaded PCL fibrous membranes for sustained release. The drug loading content and drug loading efficiency of Ropivacaine-loaded fibrous membrane are 8.7 ± 0.3 wt% and 96 ± 3 wt%, respectively. Evaluation in an animal model demonstrated prolonged anesthesia effects along with excellent biocompatibility and stability. At 72 h, the cumulative release accounted for approximately 50% of the drug loading content. This study offers novel approaches and strategies for clinical postoperative pain management and chronic pain treatment, while providing new insights and directions for the design of local anesthetic controlled-release delivery systems.

A Bioactive Disintegrable Polymer Nanoparticle for Synergistic Vascular Anticalcification

Although poly(aspartic acid) (PASP), a strong calcium chelating agent, may be potentially effective in inhibition of vascular calcification, its direct administration may lead to side effects. In this study, we employed polysuccinimide, a precursor of PASP, to prepare targeted polysuccinimide-based nanoparticles (PSI NPs) that not only acted as a prodrug but also functioned as a carrier of additional therapeutics to provide powerful synergistic vascular anticalcification effect. This paper shows that chemically modified PSI-NPs can serve as effective nanocarriers for loading of hydrophobic drugs, in addition to anticalcification and antireactive oxygen species (anti-ROS) activities. Curcumin (Cur), with high loading efficiency, was encapsulated into the NPs. The NPs were stable for 16 h in physiological conditions and then slowly dissolved/hydrolyzed to release the therapeutic PASP and the encapsulated drug. The drug release profile was found to be in good agreement with the NP dissolution profile such that complete release occurred after 48 h at physiological conditions. However, under acidic conditions, the NPs were stable, and Cur cumulative release reached only 30% after 1 week. Though highly effective in the prevention of calcium deposition, PSI NPs could not prevent the osteogenic trans-differentiation of vascular smooth muscle cells (VSMCs). The presence of Cur addressed this problem. It not only further reduced ROS level in macrophages but also prevented osteogenic differentiation of VSMCs in vitro. The NPs were examined in vivo in a rat model of vascular calcification induced by kidney failure through an adenine diet. The inclusion of Cur and PSI NPs combined the therapeutic effects of both. Cur-loaded NPs significantly reduced calcium deposition in the aorta without adversely affecting bone integrity or noticeable side effects/toxicity as examined by organ histological and serum biochemistry analyses.

An effective DLP 3D printing strategy of high strength and toughness cellulose hydrogel towards strain sensing

Photocurable 3D printing technology has outperformed extrusion-based 3D printing technology in material adaptability, resolution, and printing rate, yet is still limited by the insecure preparation and selection of photoinitiators and thus less reported. In this work, we developed a printable hydrogel that can effectively facilitate various solid or hollow structures and even lattice structures. The chemical and physical dual-crosslinking strategy combined with cellulose nanofibers (CNF) significantly improved the strength and toughness of photocurable 3D printed hydrogels. In this study, the tensile breaking strength, Young's modulus, and toughness of poly(acrylamide-co-acrylic acid)_D/cellulose nanofiber (PAM-co-PAA)_D/CNF hydrogels were 375 %, 203 % and 544 % higher than those of the traditional single chemical crosslinked (PAM-co-PAA)_S hydrogels, respectively. Notably, its outstanding compressive elasticity enabled it to recover under 90 % strain compression (about 4.12 MPa). Resultantly, the proposed hydrogel can be utilized as a flexible strain sensor to monitor the motions of human movements, such as the bending of fingers, wrists, and arms, and even the vibration of a speaking throat. The output of electrical signals can still be collected through strain even under the condition of energy shortage. In addition, photocurable 3D printing technology can provide customized services for hydrogel-based e-skin, such as hydrogel-based bracelets, fingerstall, and finger joint sleeves.

A review on chitosan and alginate-based microcapsules: Mechanism and applications in drug delivery systems

Natural polymers, like chitosan and alginate have potential of appearance, as well as the changes and handling necessary to make it acceptable vehicle for the controlled release of medicines and biomolecules. Microcapsules are characterized as micrometer-sized particulate that can be employed to store chemicals within them. In the present review, we have discussed various advantages, components of microcapsules, release mechanisms, preparation methods, and their applications in drug delivery systems. The preparation methods exhibited strong encapsulation effectiveness and may be used in a wide range of pharmaceutical and biomedical applications. The major advantages of using the microencapsulation technique are, sustained and controlled delivery of drugs, drug targeting, improvement of shelf life, stabilization, immobilization of enzymes and microorganisms. As new biomaterials are developed for the body, they are better suited to the development of pharmaceutical systems than traditional pharmaceuticals because they are more reliable, biocompatible, biodegradable, and nontoxic. Furthermore, the designed microcapsules had been capable of shielding the essential components from hostile environments. More advanced techniques could be developed in the future to facilitate the formulation and applications of microcapsules and working with the pharmaceutical and medical industries.

Multifaceted roles of pollen in the management of cancer

Oral drug delivery of microparticles demonstrates shortcomings like aggregation, decreased loading capacity and batch-to-batch variation, which limits its scale-up. Later, porous structures gained attention because of their large surface-to-volume ratio, high loading capacity and ability to carry biomacromolecules, which undergo degradation in GIT. But there are pitfalls like non-uniform particle size distribution, the impact of porogen properties, and harsh chemicals. To circumvent these drawbacks, natural carriers like pollen are explored in drug delivery, which withstands harsh environments. This property helps to subdue the acid-sensitive drug in GIT. It shows uniform particle size distribution within the species. On the other side, they contain phytoconstituents like flavonoids and polysaccharides, which possess various pharmacological applications. Therefore, pollen has the capability as a carrier system and therapeutic agent. This review focuses on pollen's microstructure, composition and utility in cancer management. The extraction strategies, characterisation techniques and chemical structure of sporopollenin exine capsule, its use in the oral delivery of antineoplastic drugs, and emerging cancer treatments like photothermal therapy, immunotherapy and microrobots have been highlighted. We have mentioned a note on the anticancer activity of pollen extract. Further, we have summarised the regulatory perspective, bottlenecks and way forward associated with pollen.

Visually controlled pulsatile release of insulin from chitosan poly-acrylic acid nanobubbles triggered by focused ultrasound

Insulin therapy is the most effective way to control the blood glucose value of diabetic patients. The most effective administration route for insulin is subcutaneous injection because bioavailability for non-injection administration is low and unstable. However, patients often need a multiple daily insulin injection regimen to control basal and postprandial blood glucose, which causes various complications. Controlled pulsatile drug release technology using ultrasound as an external stimulus source is a very promising method to avoid multiple injections of insulin. However, most of the drug-loaded microbubbles used for ultrasound-mediated treatment have a short half-life, which limits their use in controlled pulsatile drug release. More importantly, how to control insulin release is still a challenge. In this paper, chitosan poly-acrylic acid nanobubbles as drug carriers of insulin were prepared to achieve a visually controlled pulsatile release of insulin triggered by focused ultrasound. The experimental results in vivo demonstrated that nanobubbles were stable enough to achieve long-term visualization for 7 days after intramuscular injection in rats. Under the guidance of ultrasound imaging, it is visible to find the position and observe the gray values change of nanobubbles. Thus, when triggered by focused ultrasound, the amount of insulin could be accurately pulsatile released from nanobubbles. In vivo experiments in rats showed that the visually controlled pulsatile release of insulin could be achieved for a long time, up to 3 consecutive days. The blood glucose level could be repeatedly reduced by focused ultrasound irradiation with just one injection. Our research provided a promising way for visually controlled pulsatile release of insulin, which would significantly reduce the injection frequency of insulin.

A modular hydrogel bioink containing microsphere-embedded chondrocytes for 3D-printed multiscale composite scaffolds for cartilage repair

Articular cartilage tissue engineering is being considered an alternative treatment strategy for promoting cartilage damage repair. Herein, we proposed a modular hydrogel-based bioink containing microsphere-embedded chondrocytes for 3D printing multiscale scaffolds integrating the micro and macro environment of the native articular cartilage. Gelatin methacryloyl (GelMA)/alginate microsphere was prepared by a microfluidic approach, and the chondrocytes embedded in the microspheres remained viable after being frozen and resuscitated. The modular hydrogel bioink could be printed via the gel-in-gel 3D bioprinting strategy for fabricating the multiscale hydrogel-based scaffolds. Meanwhile, the cells cultured in the scaffolds showed good proliferation and differentiation. Furthermore, we also found that the composite hydrogel was biocompatible in vivo. These results indicated that the modular hydrogel-based bioinks containing microsphere-embedded chondrocytes for 3D printing multiscale scaffolds could provide a 3D multiscale environment for enhancing cartilage repairing, which would be encouraging considering the numerous alternative applications in articular cartilage tissue engineering.

Preparation strategy of hydrogel microsphere and its application in skin repair

In recent years, hydrogel microsphere has attracted much attention due to its great potential in the field of skin repair. This paper reviewed the recent progress in the preparation strategy of hydrogel microsphere and its application in skin repair. In this review, several preparation methods of hydrogel microsphere were summarized in detail. In addition, the related research progress of hydrogel microspheres for skin repair was reviewed, and focused on the application of bioactive microspheres, antibacterial microspheres, hemostatic microspheres, and hydrogel microspheres as delivery platforms (hydrogel microspheres as a microcarrier of drugs, bioactive factors, or cells) in the field of skin repair. Finally, the limitations and future prospects of the development of hydrogel microspheres and its application in the field of skin repair were presented. It is hoped that this review can provide a valuable reference for the development of the preparation strategy of hydrogel microspheres and promote the application of hydrogel microspheres in skin repair.

The recent insight in the release of anticancer drug loaded into PLGA microspheres

Cancer is a series of diseases leading to a high rate of death worldwide. Microspheres display specific characteristics that make them appropriate for a variety of biomedical purposes such as cancer therapy. Newly, microspheres have the potentials to be used as controlled drug release carriers. Recently, PLGA-based microspheres have attracted exceptional attention relating to effective drug delivery systems (DDS) because of their distinctive properties for a simple preparation, biodegradability, and high capability of drug loading which might be increased drug delivery. In this line, the mechanisms of controlled drug release and parameters that influence the release features of loaded agents from PLGA-based microspheres should be mentioned. The current review is focused on the new development of the release features of anticancer drugs, which are loaded into PLGA-based microspheres. Consequently, future perspective and challenges of anticancer drug release from PLGA-based microspheres are mentioned concisely.

Challenges and opportunities in delivering oral peptides and proteins

INTRODUCTION

Rapid advances in bioengineering enable the use of complex proteins as therapeutic agents to treat diseases. Compared with conventional small molecule drugs, proteins have multiple advantages, including high bioactivity and specificity with low toxicity. Developing oral dosage forms with active proteins is a route to improve patient compliance and significantly reduce production costs. However, the gastrointestinal environment remains a challenge to this delivery path due to enzymatic degradation, low permeability, and weak absorption, leading to reduced delivery efficiency and poor clinical outcomes.

AREAS COVERED

This review describes the barriers to oral delivery of peptides and complex proteins, current oral delivery strategies utilized and the opportunities and challenges ahead to try and circumvent these barriers. Oral protein drugs on the market and clinical trials provide insights and approaches for advancing delivery strategies.

EXPERT OPINION

Although most current studies on oral protein delivery rely on in vitro and in vivo animal data, the safety and limitations of the approach in humans remain uncertain. The shortage of clinical data limits the development of new or alternative strategies. Therefore, designing appropriate oral delivery strategies remains a significant challenge and requires new ideas, innovative design strategies and novel model systems.

Targeted release of soybean peptide from CMC/PVA hydrogels in simulated intestinal fluid and their pharmacokinetics

Carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) hydrogels loaded with soybean peptide (SPE) were fabricated via a freeze-thaw method. These hydrogels conquer barriers in simulated gastric fluid (SGF), and then release SPE in simulated intestinal fluid (SIF). The results of in vitro SPE release from these hydrogels showed that in SGF only a little of the SPE released, but in SIF the SPE was completely released. The released SPE had scavenging rates for DPPH and ABTS free radicals of 41.68 and 31.43 %. The pharmacokinetic model of SPE release from the hydrogels in SIF was studied. When the hydrogels are moved from SGF to SIF, the sorption of the shrinkage hydrogel network is entirely controlled by stress-induced relaxations. There are swollen and shrunken regions during SPE release. For SPE release into the SIF, SPE has to be freed from the weak bonds in the swollen regions by changes in the conformation of CMC and PVA. The release rate of SPE was found to be governed by the diffusion and swelling rate of the shrinkage hydrogel network. The Korsmeyer-Peppas equation diffusion exponents (n) for SPE release from the hydrogels are >2.063, indicating a super case II transport. These data demonstrate CMC/PVA hydrogels have potential applications in oral peptide delivery.

Insulin-loaded nanoparticles based on acetylated cashew gum/chitosan complexes for oral administration and diabetes treatment

Insulin is one of the most important drugs in the clinical treatment of diabetes. There is growing interest in oral insulin administration as it mimics the physiological pathway and potentially reduces side effects associated with subcutaneous injection. In this study, a nanoparticulate system was developed using acetylated cashew gum (ACG) and chitosan by the polyelectrolyte complexation method, for oral administration of insulin. The nanoparticles were characterized by size, zeta potential and encapsulation efficiency (EE%). And they had a particle size of 460 ± 11.0 nm, PDI of 0.2 ± 0.021, zeta potential of 30.6 ± 0.48 mV, and an EE% of 52.5 %. Cytotoxicity assays were performed for HT-29 cell lines. It was observed that ACG and nanoparticles did not have a significant effect on cell viability, verifying their biocompatibility. Hypoglycemic effects of the formulation were analyzed in vivo, noting that the nanoparticles reduced blood glucose by 51.0 % of baseline levels after 12 h, not inducing signs of toxicity or death. Biochemical and hematological profiles were not clinically modified. Histological study indicated no signs of toxicity. Results showed that the nanostructured system presented itself as a potential vehicle for oral insulin release.

Machine learning in accelerating microsphere formulation development

Microspheres have gained much attention from pharmaceutical and medical industry due to the excellent biodegradable and long controlled-release characteristics. However, the drug release behavior of microspheres is influenced by complicated formulation and manufacturing factors. The traditional formulation development of microspheres is intractable and inefficient by the experimentally trial-and-error methods. This research aims to build a prediction model to accelerate microspheres product development for small-molecule drugs by machine learning (ML) techniques. Two hundred eighty-six microsphere formulations with small-molecule drugs were collected from the publications and pharmaceutical company, including the dissolution temperature at both 37 ℃ and 45 ℃. After the comparison of fourteen ML approaches, the consensus model achieved accurate predictions for the validation set at 37 ℃ and 45 ℃ (R² = 0.880 vs. R² = 0.958), indicating the good performance to predict the in vitro drug release profiles at both 37 ℃ and 45 ℃. Meanwhile, the models revealed the feature importance of formulations, which offered meaningful insights to the microspheres development. Experiments of microsphere formulations further validated the accuracy of the consensus model. Furthermore, molecular dynamics (MD) simulation provided a microscopic view of the preparation process of microspheres. In conclusion, the prediction model of microsphere formulations for small-molecule drugs was successfully built with high accuracy, which is able to accelerate microspheres product development and promote the quality control of microspheres for the pharmaceutical industry.

Multilayered polymer coating modulates mucoadhesive and biological properties of camptothecin-loaded lipid nanocapsules

Lipid core nanocapsules (NCs) coated with multiple polymer layers were rationally designed as a potential approach for the colonic delivery of camptothecin (CPT). Chitosan (CS), hyaluronic acid (HA) and hypromellose phthalate (HP) were selected as coating materials, to modulate the mucoadhesive and permeability properties of CPT regarding the improvement of local and targeted action in the colon cancer cells. NCs were prepared by emulsification/solvent evaporation method and coated with multiple polymer layers by polyelectrolyte complexation technique. NCs exhibited spherical shape, negative zeta potential, and size ranged from 184 to 252 nm. The high efficiency of CPT incorporation (>94%) was evidenced. The ex vivo permeation assay showed that nanoencapsulation reduced the permeation rate of CPT through the intestinal mucosa by up to 3.5 times, and coating with HA and HP reduced the permeation percentage by 2 times when compared to NCs coated only with CS. The mucoadhesive capacity of NCs was demonstrated in gastric and enteric pH. Nanoencapsulation did not reduce the antiangiogenic activity of CPT and, additionally, it was observed that nanoencapsulation resulted in localized antiangiogenic action of CPT.

Poly(succinimide) nanoparticles as reservoirs for spontaneous and sustained synthesis of poly(aspartic acid) under physiological conditions: potential for vascular calcification therapy and oral drug delivery

This paper describes the preparation of poly(succinimide) nanoparticles (PSI NPs) and investigates their properties and characteristics. Employing direct and inverse precipitation methods, stable PSI NPs with tunable size and narrow dispersity were prepared without the use of any stabilizer or emulsifier. It was demonstrated that PSI NPs convert to poly(aspartic acid) (PASP) gradually under physiological conditions (37 °C, pH 7.4), while remaining stable under mildly acidic conditions. The dissolution profile was tuned and delayed by chemical modification of PSI. Through grafting a fluorophore to the PSI backbone, it was also demonstrated that such a spontaneous conversion could offer great potential for oral delivery of therapeutic agents to the colon. Sustained PASP synthesis also contributed to a sustained reduction of reactive oxygen species induced by iron. Furthermore, PSI NPs effectively prevented in vitro calcification of smooth muscle cells. This was attributed to the chelation of calcium ions to PASP, thereby inhibiting calcium deposition, because under cell culture conditions PSI NPs serve as reservoirs for the sustained synthesis of PASP. Overall, this study sheds light on the preparation and features of biocompatible and biodegradable PSI-based NPs and paves the way for further research to discover as-yet unfulfilled potential of this polymer in the form of nanoparticles.

Rational Design of Biomaterials to Potentiate Cancer Thermal Therapy

Cancer thermal therapy, also known as hyperthermia therapy, has long been exploited to eradicate mass lesions that are now defined as cancer. With the development of corresponding technologies and equipment, local hyperthermia therapies such as radiofrequency ablation, microwave ablation, and high-intensity focused ultrasound, have has been validated to effectively ablate tumors in modern clinical practice. However, they still face many shortcomings, including nonspecific damages to adjacent normal tissues and incomplete ablation particularly for large tumors, restricting their wide clinical usage. Attributed to their versatile physiochemical properties, biomaterials have been specially designed to potentiate local hyperthermia treatments according to their unique working principles. Meanwhile, biomaterial-based delivery systems are able to bridge hyperthermia therapies with other types of treatment strategies such as chemotherapy, radiotherapy and immunotherapy. Therefore, in this review, we discuss recent progress in the development of functional biomaterials to reinforce local hyperthermia by functioning as thermal sensitizers to endow more efficient tumor-localized thermal ablation and/or as delivery vehicles to synergize with other therapeutic modalities for combined cancer treatments. Thereafter, we provide a critical perspective on the further development of biomaterial-assisted local hyperthermia toward clinical applications.

Potential applications of drug delivery technologies against radiation enteritis

INTRODUCTION

The incidence of abdominal tumors, such as colorectal and prostate cancers, continually increases. Radiation therapy is widely applied in the clinical treatment of patients with abdominal/pelvic cancers, but it often unfortunately causes radiation enteritis (RE) involving the intestine, colon, and rectum. However, there is a lack of suitable treatment options for effective prevention and treatment of RE.

AREAS COVERED

Conventional clinical drugs for preventing and treating RE are usually applied by enemas and oral administration. Innovative gut-targeted drug delivery systems including hydrogels, microspheres, and nanoparticles are proposed to improve the prevention and curation of RE.

EXPERT OPINION

The prevention and treatment of RE have not attracted sufficient attention in the clinical practice, especially compared to the treatment of tumors, although RE takes patients great pains. Drug delivery to the pathological sites of RE is a huge challenge. The short retention and weak targeting of conventional drug delivery systems affect the therapeutic efficiency of anti-RE drugs. Novel drug delivery systems including hydrogels, microspheres, and nanoparticles can allow drugs long-term retention in the gut and targeting the inflammation sites to alleviate radiation-induced injury.

Electrospray-Assisted Fabrication of Dextran-Whey Protein Isolation Microcapsules for the Encapsulation of Selenium-Enriched Peptide

Selenium-enriched peptide (SP, selenopeptide) is an excellent organic selenium supplement that has attracted increasing attention due to its superior physiological effects. In this study, dextran-whey protein isolation-SP (DX-WPI-SP) microcapsules were fabricated via high-voltage electrospraying technology. The results of preparation process optimization showed that the optimized preparation process parameters were 6% DX (w/v), feeding rate Q = 1 mL/h, voltage U = 15 kV, and receiving distance H = 15 cm. When the content of WPI (w/v) was 4-8%, the average diameter of the as-prepared microcapsules was no more than 45 μm, and the loading rate for SP ranged from ~46% to ~37%. The DX-WPI-SP microcapsules displayed excellent antioxidant capacity. The thermal stability of the microencapsulated SP was improved, which was attributed to the protective effects of the wall materials for SP. The release performance was investigated to disclose the sustained-release capacity of the carrier under different pH values and an in-vitro-simulated digestion environment. The digested microcapsule solution showed negligible influence on the cellular cytotoxicity of Caco-2 cells. Overall, our work provides a facile strategy of electrospraying microcapsules for the functional encapsulation of SP and witnesses a broad prospect that the DX-WPI-SP microcapsules can exhibit great potential in the food processing field.

Soft robot-enabled controlled release of oral drug formulations

The creation of highly effective oral drug delivery systems (ODDSs) has long been the main objective of pharmaceutical research. Multidisciplinary efforts involving materials, electronics, control, and pharmaceutical sciences encourage the development of robot-enabled ODDSs. Compared with conventional rigid robots, soft robots potentially offer better mechanical compliance and biocompatibility with biological tissues, more versatile shape control and maneuverability, and multifunctionality. In this paper, we first describe and highlight the importance of manipulating drug release kinetics, i.e. pharmaceutical kinetics. We then introduce an overview of state-of-the-art soft robot-based ODDSs comprising resident, shape-programming, locomotive, and integrated soft robots. Finally, the challenges and outlook regarding future soft robot-based ODDS development are discussed.

An Overview of Taste-Masking Technologies: Approaches, Application, and Assessment Methods

It is well-known that plenty of active pharmaceutical ingredients (API) inherently possess an unpleasant taste, which influences the acceptance of patients, especially children. Therefore, manufacturing taste-masked dosage forms has attracted a lot of attention. This review describes in detail the taste-masking technologies based on the difference in the taste transmission mechanism which is currently available. In particular, the review highlights the application of various methods, with a special focus on how to screen the appropriate masking technology according to the properties of API. Subsequently, we overviewed how to assess taste-masking efficacy, guiding researchers to rationally design taste-masking formulations.

A novel insulin delivery system by β cells encapsulated in microcapsules

Introduction: Diabetes is a growing epidemic worldwide and requires effective clinical therapies. In recent years, β-cell transplantation has emerged as a promising treatment for diabetes, and an encapsulation approach has been proposed to ameliorate this treatment. Methods: Microfluidic technology had been used to generate microcapsules using a porous sodium alginate shell and a core containing β cells. The microcapsules were transplanted into diabetic mice and the therapeutic effect was measured. Results: Porous hydrogel shell allows exchange of small molecules of nutrients while protecting beta cells from immune rejection, while the core ensures high activity of the encapsulated cells. The glucose control effect of the microcapsules were more durable and better than conventional methods. Discussion: We believe that this system, which is composed of biocompatible porous hydrogel shell and enables highly activity of encapsulated β cells, can enhance therapeutic efficacy and has promising clinical applications.

Promising Role of Polylactic Acid as an Ingenious Biomaterial in Scaffolds, Drug Delivery, Tissue Engineering, and Medical Implants: Research Developments, and Prospective Applications

In the present scenario, the research is now being focused on the naturally occurring polymers that can gradually replace the existing synthetic polymers for the development of bio composites having applications in medical surgeries and human implants. With promising mechanical properties and bio compatibility with human tissues, poly lactic acid (PLA) is now being viewed as a future bio material. In order to examine the applicability of PLA in human implants, the current article sheds light on the synthesis of PLA and its various copolymers used to alter its physical and mechanical properties. In the latter half, various processes used for the fabrication of biomaterials are discussed in detail. Finally, biomaterials that are currently in use in the field of biomedical (Scaffolding, drug delivery, tissue engineering, medical implants, derma, cosmetics, medical surgeries, and human implants) are represented with respective advantages in the sphere of biomaterials.

Preparation and morphology control of porous microspheres of different crystalline polymers

Controlling the surface morphology of degradable polymer porous microspheres with alkanes as porogens using the emulsion solvent evaporation method.

Development of a Workflow to Engineer Tailored Microparticles Via Inkjet Printing

PURPOSE

New drug development and delivery approaches result in an ever-increasing demand for tailored microparticles with defined sizes and structures. Inkjet printing technologies could be promising new processes to engineer particles with defined characteristics, as they are created to precisely deliver liquid droplets with high uniformity.

METHODS

D-mannitol was used as a model compound alone or co-processed with the pore former agent ammonium bicarbonate, and the polymer polyethylene glycol 200. Firstly, a drop shape analyzer was used to characterize and understand ink/substrate interactions, evaporation, and solidification kinetics. Consequently, the process was transferred to a laboratory-scale inkjet printer and the resulting particles collected, characterized and compared to others obtained via an industrial standard technique.

RESULTS

The droplet shape analysis allowed to understand how 3D structures are formed and helped define the formulation and process parameters for inkjet printing. By adjusting the drop number and process waveform, spherical particles with a mean size of approximately 100 µm were obtained. The addition of pore former and polymer allowed to tailor the crystallization kinetics, resulting in particles with a different surface (i.e., spike-like surface) and bulk (e.g. porous and non-porous) structure.

CONCLUSION

The workflow described enabled the production of 3D structures via inkjet printing, demonstrating that this technique can be a promising approach to engineer microparticles.

pH-sensitive O-carboxymethyl chitosan/sodium alginate nanohydrogel for enhanced oral delivery of insulin

Oral drug delivery is considered the most preferred mode of treatment because of its high patient compliance and minimal invasiveness. However, the oral delivery of protein drug has been a difficult problem which restricts its application due to the unstable and inefficient penetration of protein in the gastrointestinal tract. In this study, a novel OCMC/SA nanohydrogel was prepared by using of O-carboxymethyl chitosan (OCMC) and sodium alginate (SA) to solve the problem. The OCMC/SA had a typical nanostructure, which was helpful to increase the specific surface area and enhanced the bioavailability of the drugs. OCMC/SA had a high drug loading capacity and realized passive drug targeting function by responding to the different pH value of the microenvironment. It could have a certain protective effect on drugs in strong acid circumstances, while its structure got loosed and effectively released drugs in intestinal circumstances. OCMC/SA could release the drug for >12 h, and the released insulin could maintain high activity. OCMC/SA nanohydrogel showed promising results in type 1 diabetic rats, and its pharmacological bioavailability was 6.57 %. In conclusion, this study constructed a novel OCMC/SA nanohydrogel, which had a lot of exciting characteristics and provided a new strategy for oral drug delivery.

Generation of dorsoventral human spinal cord organoids via functionalizing composite scaffold for drug testing

The spinal cord possesses highly complex, finely organized cytoarchitecture guided by two dorsoventral morphogenic organizing centers. Thus, generation of human spinal cord tissue in vitro is challenging. Here, we demonstrated a novel method for generation of human dorsoventral spinal cord organoids using composite scaffolds. Specifically, the spinal cord ventralizing signaling Shh agonist (SAG) was loaded into a porous chitosan microsphere (PCSM), then thermosensitive Matrigel was coated on the surface to form composite microspheres with functional sustained-release SAG, termed as PCSM-Matrigel@SAG. Using PCSM-Matrigel@SAG as the core to induce 3D engineering of human spinal cord organoids from human pluripotent stem cells (ehSC-organoids), we found ehSC-organoids could form dorsoventral spinal cord-like cytoarchitecture with major domain-specific progenitors and neurons. Besides, these ehSC-organoids also showed functional calcium activity. In summary, these ehSC-organoids are of great significance for modeling spinal cord development, drug screening as 3D models for motor neuron diseases, and spinal cord injury repair.

Review of the toxicity and potential molecular mechanisms of parental or successive exposure to environmental pollutants in the model organism Caenorhabditis elegans

Environmental pollutants such as heavy metals, nano/microparticles, and organic compounds have been detected in a wide range of environmental media, causing long-term exposure in various organisms and even humans through breathing, contacting, ingestion, and other routes. Long-term exposure to environmental pollutants in organisms or humans promotes exposure of offspring to parental and environmental pollutants, and subsequently results in multiple biological defects in the offspring. This review dialectically summarizes and discusses the existing studies using Caenorhabditis elegans (C. elegans) as a model organism to explore the multi/transgenerational toxicity and potential underlying molecular mechanisms induced by environmental pollutants following parental or successive exposure patterns. Parental and successive exposure to environmental pollutants induces various biological defects in C. elegans across multiple generations, including multi/transgenerational developmental toxicity, neurotoxicity, reproductive toxicity, and metabolic disturbances, which may be transmitted to progeny through reactive oxygen species-induced damage, epigenetic mechanisms, insulin/insulin-like growth factor-1 signaling pathway. This review aims to arouse researchers' interest in the multi/transgenerational toxicity of pollutants and hopes to explore the possible long-term effects of environmental pollutants on organisms and even humans, as well as to provide constructive suggestions for the safety and management of emerging alternatives.

Senkyunolide H Affects Cerebral Ischemic Injury through Regulation on Autophagy of Neuronal Cells via P13K/AKT/mTOR Signaling Pathway

Cerebral ischemia (CI) is associated with high global incidence and risk; therefore, its rapid and reliable therapeutic management is essential for protecting patients' lives and improving health. Senkyunolide H (SH) is remarkably effective against phlebosclerosis, oxidation, and apoptosis. Blood-brain barrier is the main obstacle impeding the delivery of drugs and xenobiotics to brain areas. Drugs' loading in nanoparticles can overcome the blood-brain barrier obstacle and thus directly and completely act on brain tissue, and such a loading can also change the half-life of drugs in vivo and lower the dosage requirement of drugs. In this study, we loaded the SH in lipid nanoparticles to improve its delivery to the brain for the therapy of CI. Thus, this study preliminarily analyzed the mechanism of SH-loaded nanoparticles in CI. The SH-loaded lipid nanoparticles were prepared and characterized with electron microscopy and PS potentiometery. The SH-loaded nanoparticles were intraperitoneally administered to CI-induced rats and brain tissue water content, and neuronal apoptosis and autophagy-associated proteins were determined. Our assays revealed SH-loaded nanoparticle's ability to reduce nerve injury and brain tissue water content in rats with CI and inhibit the apoptosis and autophagy of their neuronal cells (NCs). Additionally, under intervention with SH-loaded nanoparticles, P13K/AKT/mTOR pathway-associated proteins in brain tissue of rats decreased. As the assay results showed, SH-loaded nanoparticles can suppress the autophagy of NCs through medicating P13K/AKT/mTOR pathway and lower apoptosis, thus delivering the effect of treating CI. Results of this study indicate SH-loaded nanoparticles as promising strategy for delivery SH to brain areas for treating CI.