Controlled Interfacial Polymer Self-Assembly Coordinates Ultrahigh Drug Loading and Zero-Order Release in Particles Prepared under Continuous Flow

A Thin Polymer Layer Enables Peptide-Polycation Complexes with Ultrahigh Efficient Encapsulation

A monolayer encapsulation is a new opportunity for engineering a system with high drug loading, but immobilizing polymer molecules on the surface of individual peptide nanoparticles is still an ongoing challenge. Herein, an individual peptide nanoparticle encapsulation strategy is proposed via surface adsorption, in which peptide molecules undergo granulation and subsequently aggregate with polymer molecules, forming a network via electrostatic interactions. Under the water phase, surplus polymer molecules dissolve, leading to a single nanoparticle encapsulation with a core-shell structure. As expected, the dense interfacial layer on the peptide nanoparticle surface achieves a superior loading degree of up to 95.4%. What's more, once the core-shell structure is established, the peptide mass fraction in individual encapsulation always exceeds 90% even under fierce external force. Following the individual nanoparticle encapsulation, the insulin-polycation complex (InsNp@PEI) reduces the inflammation from polymer and displays an effective glycemic control in type 1 diabetes. Overall, the newly developed single surface decoration encapsulates peptides with ultrahigh efficiency and opens up the possibility for further encapsulation.

Microfluidic preparation of monodisperse PLGA-PEG/PLGA microspheres with controllable morphology for drug release

Monodisperse biodegradable polymer microspheres show broad applications in drug delivery and other fields. In this study, we developed an effective method that combines microfluidics with interfacial instability to prepare monodispersed poly(lactic-co-glycolic acid)-b-polyethylene glycol (PLGA-PEG)/poly(lactic-co-glycolic acid) (PLGA) microspheres with tailored surface morphology. By adjusting the mass ratio of PLGA-PEG to PLGA, the concentration of stabilizers and the type of PLGA, we generated microspheres with various unique folded morphologies, such as "fishtail-like", "lace-like" and "sponge-like" porous structures. Additionally, we demonstrated that risperidone-loaded PLGA-PEG/PLGA microspheres with these folded morphologies significantly enhanced drug release, particularly in the initial stage, by exhibiting a logarithmic release profile. This feature could potentially address the issue of delayed release commonly observed in sustained-release formulations. This study presents a straightforward yet effective approach to construct precisely engineered microspheres offering enhanced control over drug release dynamics.

Glypican-3-targeted macrophages delivering drug-loaded exosomes offer efficient cytotherapy in mouse models of solid tumours

Cytotherapy is a strategy to deliver modified cells to a diseased tissue, but targeting solid tumours remains challenging. Here we design macrophages, harbouring a surface glypican-3-targeting peptide and carrying a cargo to combat solid tumours. The anchored targeting peptide facilitates tumour cell recognition by the engineered macrophages, thus enhancing specific targeting and phagocytosis of tumour cells expressing glypican-3. These macrophages carry a cargo of the TLR7/TLR8 agonist R848 and INCB024360, a selective indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor, wrapped in C16-ceramide-fused outer membrane vesicles (OMV) of Escherichia coli origin (RILO). The OMVs facilitate internalization through caveolin-mediated endocytosis, and to maintain a suitable nanostructure, C16-ceramide induces membrane invagination and exosome generation, leading to the release of cargo-packed RILOs through exosomes. RILO-loaded macrophages exert therapeutic efficacy in mice bearing H22 hepatocellular carcinomas, which express high levels of glypican-3. Overall, we lay down the proof of principle for a cytotherapeutic strategy to target solid tumours and could complement conventional treatment.

Prolonged joint cavity retention of tranexamic acid achieved by a solid-in-oil-in-gel system: A preliminary study

Tranexamic acid (TXA) is an anti-fibrinolysis agent widely used in postoperative blood loss management. As a highly water-soluble drug, TXA is suffering from rapid clearance from the action site, therefore, large amount of drug is required when administered either by intravenously or topically. In this study, a TXA preparation with prolonged action site residence was designed using the nano-micro strategy. TXA nanoparticles were dispersed in oil by emulsification followed by lyophilization to give a solid-in-oil suspension, which was used as the oil phase for the preparation of TXA-loaded solid-in-oil-in-water (TXA@S/O/W) system. The particle size of TXA in oil was 207.4 ± 13.50 nm, and the particle size of TXA@S/O/W was 40.5 μm. The emulsion-in-gel system (TXA@S/O/G) was prepared by dispersing TXA@S/O/W in water solution of PLGA-b-PEG-b-PLGA (PPP). And its gelling temperature was determined to be 26.6 ℃ by a rheometer. Sustained drug release was achieved by TXA@S/O/G with 72.85 ± 7.52 % of TXA released at 120 h. Formulation retention at the joint cavity was studied by live imaging, and the fluorescent signals dropped gradually during one week. Drug escape from the injection site via drainage and absorption was investigated by a self-made device and plasma TXA concentration determination, respectively. TXA@S/O/G showed the least drug drainage during test, while more than 70 % of drug was drained in TXA@S/O/W group and TXA solution group. Besides, low yet steady plasma TXA concentration (less than 400 ng/mL) was found after injecting TXA@S/O/G into rat knees at a dosage of 2.5 mg/kg, which was much lower than those of TXA dissolved in PPP gel or TXA solution. In conclusion, sustained drug release as well as prolonged action site retention were simultaneously achieved by the designed TXA@S/O/G system. More importantly, due to the steady plasma concentration, this strategy could be further applied to other highly water-soluble drugs with needs on sustained plasma exposure.

Hierarchical Self-Assembly Molecular Building Blocks as Intelligent Nanoplatforms for Ovarian Cancer Theranostics

Hierarchical self-assembly from simple building blocks to complex polymers is a feasible approach to constructing multi-functional smart materials. However, the polymerization process of polymers often involves challenges such as the design of building blocks and the drive of external energy. Here, a hierarchical self-assembly with self-driven and energy conversion capabilities based on p-aminophenol and diethylenetriamine building blocks is reported. Through β-galactosidase (β-Gal) specific activation to the self-assembly, the intelligent assemblies (oligomer and superpolymer) with excellent photothermal and fluorescent properties are dynamically formed in situ, and thus the sensitive multi-mode detection of β-Gal activity is realized. Based on the overexpression of β-Gal in ovarian cancer cells, the self-assembly superpolymer is specifically generated in SKOV-3 cells to achieve fluorescence imaging. The photothermal therapeutic ability of the self-assembly oligomer (synthesized in vitro) is evaluated by a subcutaneous ovarian cancer model, showing satisfactory anti-tumor effects. This work expands the construction of intelligent assemblies through the self-driven cascade assembly of small molecules and provides new methods for the diagnosis and treatment of ovarian cancer.

Host-Directed Virus-Mimicking Particles Interacting with the ACE2 Receptor Competitively Block Coronavirus SARS-CoV-2 Entry

Herein, we fabricate host-directed virus-mimicking particles (VMPs) to block the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into host cells through competitive inhibition enabled by their interactions with the angiotensin-converting enzyme 2 (ACE2) receptor. A microfluidic platform is developed to fabricate a lipid core of the VMPs with a narrow size distribution and a low level of batch-to-batch variation. The resultant solid lipid nanoparticles are decorated with an average of 231 or 444 Spike S1 RBD protrusions mimicking either the original SARS-CoV-2 or its delta variant, respectively. Compared with that of the nonfunctionalized core, the cell uptake of the functionalized VMPs is enhanced with ACE2-expressing cells due to their strong interactions with the ACE2 receptor. The fabricated VMPs efficiently block the entry of SARS-CoV-2 pseudovirions into host cells and suppress viral infection. Overall, this study provides potential strategies for preventing the spread of SARS-CoV-2 or other coronaviruses employing the ACE2 receptor to enter into host cells.

Advancements in nanoscale delivery systems: optimizing intermolecular interactions for superior drug encapsulation and precision release

Nanoscale preparations, such as nanoparticles, micelles, and liposomes, are increasingly recognized in pharmaceutical technology for their high capability in tailoring the pharmacokinetics of the encapsulated drug within the body. These preparations have great potential in extending drug half-life, reducing dosing frequency, mitigating drug side effects, and enhancing drug efficacy. Consequently, nanoscale preparations offer promising prospects for the treatment of metabolic disorders, malignant tumors, and various chronic diseases. Nevertheless, the complete clinical potential of nanoscale preparations remains untapped due to the challenges associated with low drug loading degrees and insufficient control over drug release. In this review, we comprehensively summarize the vital role of intermolecular interactions in enhancing encapsulation and controlling drug release within nanoscale delivery systems. Our analysis critically evaluates the characteristics of common intermolecular interactions and elucidates the techniques employed to assess them. Moreover, we highlight the significant potential of intermolecular interactions in clinical translation, particularly in the screening and optimization of preparation prescriptions. By attaining a deeper understanding of intermolecular interaction properties and mechanisms, we can adopt a more rational approach to designing drug carriers, leading to substantial advancements in the application and clinical transformation of nanoscale preparations. Moving forward, continued research in this field offers exciting prospects for unlocking the full clinical potential of nanoscale preparations and revolutionizing the field of drug delivery.

A Layer-by-Layer Self-Assembled Bio-Macromolecule Film for Stable Zinc Anode

Side reactions on zinc metal (Zn) anodes are formidable issues that cause limited battery life of aqueous zinc-ion batteries (AZIBs). Here, a facile and controllable layer-by-layer (LbL) self-assembly technique is deployed to construct an ion-conductive and mechanically robust electrolyte/anode interface for stabilizing the Zn anode. The LbL film consists of two natural and biodegradable bio-macromolecules, chitosan (CS) and sodium alginate (SA). It is shown that such an LbL film tailors the solvation sheath of Zn ions and facilitates the oriented deposition of Zn. Symmetric cells with the four double layers of CS/SA ((CS/SA)4 -Zn) exhibit stable cycles for over 6500 h. The (CS/SA)4 -Zn||H2 V3 O8 coin cell maintains a specific capacity of 125.5 mAh g-1 after 14 000 cycles. The pouch cell with an electrode area of 5 × 7 cm2 also presents a capacity retention of 83% for over 500 cycles at 0.1 A g-1 . No obvious dendrites are observed after long cycles in both symmetric and full cells. Given the cost-effective material and fabrication, and environmental friendliness of the LbL films, this Zn protection strategy may boost the industrial application of AZIBs.

Insights into the Mechanism of Supramolecular Self-Assembly in the Astragalus membranaceus-Angelica sinensis Codecoction

Astragalus membranaceus (Fisch.) Bge. (AM) and Angelica sinensis (Oliv.) Diels (AS) constitute a classic herb pair in prescriptions to treat myocardial fibrosis. To date, research on the AM-AS herb pair has mainly focused on the chemical compositions associated with therapeutic efficacy. However, supermolecules actually exist in herb codecoctions, and their self-assembly mechanism remains unclear. In this study, supermolecules originating from AM-AS codoping reactions (AA-NPs) were first reported. The chemical compositions of AA-NPs showed a dynamic self-assembly process. AA-NPs with different decoction times had similar surface groups and amorphous states; however, the size distributions of these nanoparticles might be different. Taking the interaction between Z-ligustilide and astragaloside IV as an example to understand the self-assembly mechanism of AA-NPs, it was found that the complex could be formed with a molar ratio of 2:1. Later, AA-NPs were proven to be effective in the treatment of myocardial fibrosis both in vivo and in vitro, the in-depth mechanisms of which were related to the recovery of cardiac function, reduced collagen deposition, and inhibition of the endothelial-to-mesenchymal transition that occurred in the process of myocardial fibrosis. Thus, AA-NPs may be the chemical material basis of the molecular mechanism of the AM-AS decoction in treating isoproterenol-induced myocardial fibrosis. Taken together, this work provides a supramolecular strategy for revealing the interaction between effective chemical components in herb-pair decoctions.