Construction of intelligent drug delivery system based on polysaccharide-derived polymer micelles: A review

Structural properties, bioactivities, structure-activity relationships and bio-applications of polysaccharides from Auricularia auricula: A review

Auricularia auricula (A. auricula), is a medicinal and edible fungus in China for thousands of years with rich nutrition and delicious taste. The main active ingredient of A. auricula is polysaccharide, which has antitumor, hypoglycemic, antioxidant, and immune regulation bioactivities. It is widely recognized that the biological activity of polysaccharides is closely related to the chemical structure and advanced structure. In terms of polysaccharides extracted from A. auricula (AAPs), there were distinguished structures reported due to the different original resources and extraction methods, leading to various bioactivities. However, the structure-activity relationship of AAPs has scarcely been reviewed till now. In addition, polysaccharides were found to have specific self-assembly properties recently, together with their bioactivities, endowing them with unique physicochemical properties. Nowadays, an increasing number of polysaccharides, such as cellulose, chitin, and pectin, have been used to construct various functional materials in the fields of food, cosmetics, and biomedical materials. Therefore, the construction of functional materials by AAPs is of great research significance. This article aims to provide a systematic review of the structure-activity relationship of AAPs and summarize the functional materials constructed based on AAPs to provide theoretical references for further research and application of AAPs.

Preparation of a minocycline polymer micelle thermosensitive gel and its application in spinal cord injury

Neuroprotection is an important approach for the treatment of spinal cord injury (SCI). Minocycline (MC), a known neuroprotective agent, has been utilized for SCI treatment, but its therapeutic effect is limited by instability and low bioavailability. Herein, we developed an innovative micellar thermosensitive hydrogel (MCPP-M-gel) that encapsulates MC in polyethylene glycol (PEG)-poly(lactide-co-glycolic acid) (PLGA) micelles to enhance its therapeutic efficacy in a rat model of SCI. The micelles were synthesized via the thin-film hydration method and characterized for encapsulation efficiency, particle size, zeta potential, and polydispersity index (PDI). MCPP-M-gel demonstrated favorable physico-mechanical properties and extended MC release over 72 hours in vitro without cytotoxic effects on neural crest-derived ectoderm mesenchymal stem cells (EMSCs). Thereafter, MC, MCPP-M, MCPP-M-gel and a blank micellar thermosensitive gel were injected into the injured site of SCI rats. Histopathological evaluation demonstrated that MCPP-M-gel could promote neuronal regeneration at the injured site of the SC after 28 days. Immunofluorescence techniques revealed that MCPP-M-gel increased the expression of neuronal class III β-tubulin (Tuj1), myelin basic protein (MBP), growth-associated protein 43 (GAP43), neurofilament protein-200 (NF-200) and nestin as well as reduced glial-fibrillary acidic protein (GFAP) expression in damaged areas of the SC. In conclusion, this study innovatively developed MCPP-M-gel based on a PEG-PLGA copolymer as a biomaterial, laying a solid foundation for further research and application of MCPP-M-gel in SCI models or other neurodegenerative diseases.

Poly(Photosensitizer-Prodrug) Unimolecular Micelles for Chemo-Photodynamic Synergistic Therapy of Antitumor and Antibacteria

It is crucial to use simple methods to prepare stable polymeric micelles with multiple functions for cancer treatment. Herein, via a "bottom-up" strategy, we reported the fabrication of β-CD-(PEOSMA-PCPTMA-PPEGMA)21 (βPECP) unimolecular micelles that could simultaneously treat tumors and bacteria with chemotherapy and photodynamic therapy (PDT). The unimolecular micelles consisted of a 21-arm β-cyclodextrin (β-CD) core as a macromolecular initiator, photosensitizer eosin Y (EOS-Y) monomer EOSMA, anticancer drug camptothecin (CPT) monomer, and a hydrophilic shell PEGMA. Camptothecin monomer (CPTMA) could achieve controlled release of the CPT due to the presence of responsively broken disulfide bonds. PEGMA enhanced the biocompatibility of micelles as a hydrophilic shell. Two βPECP with different lengths were synthesized by modulating reaction conditions and the proportion of monomers, which both were self-assembled to unimolecular micelles in water. βPECP unimolecular micelles with higher EOS-Y/CPT content exhibited more excellent 1O2 production, in vitro drug release efficiency, higher cytotoxicity, and superior antibacterial activity. Also, we carried out simulations of the self-assembly and CPT release process of micelles, which agreed with the experiments. This nanosystem, which combines antimicrobial and antitumor functions, provides new ideas for bacteria-mediated tumor clinical chemoresistance.

Micellar delivery systems of bioactive compounds for precision nutrition

Rapid changes in lifestyle and the increasingly hectic pace of life have led to a rise in chronic diseases, such as obesity, inflammatory bowel disease, liver disease, and cancer, posing significant threats to public health. In response to these challenges, precision nutrition (PN) has emerged as a secure and effective intervention aiming at human health and well-being. Bioactive compounds (bioactives), including carotenoids, polyphenols, vitamins, and polyunsaturated fatty acids, exhibit a range of beneficial properties, e.g., antioxidant and anti-inflammatory effects. These properties make them promising candidates for preventing or treating chronic diseases and promoting human health. However, bioactives might have different challenges when incorporated into food matrices and oral administration, including low water solubility, poor physiochemical stability, and low absorption efficiency. This limits them to achieve the health benefits in the body. Numerous strategies have been developed and utilized to encapsulate and deliver bioactives. Micellar delivery systems, due to their unique core-shell structure, play a pivotal role in improving the stability, solubility, and bioavailability of these bioactives. Moreover, through innovative design strategies, micellar delivery systems can be tailored to offer targeted and controlled release, thus maximizing the potential of bioactives in PN applications. This chapter reveals details about the preparation methods and properties of micelles and highlights the strategies to modulate the properties of polymeric micelles. Afterwards, the application of polymeric micelles in the delivery of bioactives and the corresponding PN, including controlled release, organ-targeting ability, and nutritional intervention for chronic disease are summarized.

Polymersomes as Innovative, Stimuli-Responsive Platforms for Cancer Therapy

This review addresses the urgent need for more targeted and less toxic cancer treatments by exploring the potential of multi-responsive polymersomes. These advanced nanocarriers are engineered to deliver drugs precisely to tumor sites by responding to specific stimuli such as pH, temperature, light, hypoxia, and redox conditions, thereby minimizing the side effects associated with traditional chemotherapy. We discuss the design, synthesis, and recent applications of polymersomes, emphasizing their ability to improve therapeutic outcomes through controlled drug release and targeted delivery. Moreover, we highlight the critical areas for future research, including the optimization of polymersome-biological interactions and biocompatibility, to facilitate their clinical adoption. Multi-responsive polymersomes emerge as a promising development in nanomedicine, offering a pathway to safer and more effective cancer treatments.

Stimuli responsiveness of recent biomacromolecular systems (concept to market): A review

Stimuli responsive delivery systems, also known as smart/intelligent drug delivery systems, are specialized delivery vehicles designed to provide spatiotemporal control over drug release at target sites in various diseased conditions, including tumor, inflammation and many others. Recent advances in the design and development of a wide variety of stimuli-responsive (pH, redox, enzyme, temperature) materials have resulted in their widespread use in drug delivery and tissue engineering. The aim of this review is to provide an insight of recent nanoparticulate drug delivery systems including polymeric nanoparticles, dendrimers, lipid-based nanoparticles and the design of new polymer-drug conjugates (PDCs), with a major emphasis on natural along with synthetic commercial polymers used in their construction. Special focus has been placed on stimuli-responsive polymeric materials, their preparation methods, and the design of novel single and multiple stimuli-responsive materials that can provide controlled drug release in response a specific stimulus. These stimuli-sensitive drug nanoparticulate systems have exhibited varying degrees of substitution with enhanced in vitro/in vivo release. However, in an attempt to further increase drug release, new dual and multi-stimuli based natural polymeric nanocarriers have been investigated which respond to a mixture of two or more signals and are awaiting clinical trials. The translation of biopolymeric directed stimuli-sensitive drug delivery systems in clinic demands a thorough knowledge of its mechanism and drug release pattern in order to produce affordable and patient friendly products.