ABSTRACT Human serum albumin (HSA) has attracted significant attention in drug delivery since the approval of Abraxane in 2005. Abraxane is a nanoparticle albumin-bound paclitaxel (nab-PTX) formulation. Although HSA offers advantages such as prolonged circulation time (half-life ~19 days) and intrinsic hydrophobic pockets, the translation of other HSA-based nanomedicines remains limited. In fact, the significant differences between native and pharmaceutical HSA in protein structure and biological interactions could hinder their translational use in drug delivery. In this study, we demonstrate that pharmaceutical HSA (α-helix = 17%) is structurally denatured compared with native HSA (α-helix = 68%), leading to rapid clearance (<1 h) from the circulation and that drug loading is driven by pharmaceutical HSA’s amphiphilicity rather than by its hydrophobic pockets. Here, we revealed that Nab-PTX is composed of protein-coated PTX solid cores. These nanosystems have insufficient surface charge (ζ = −13.7 mV), leading to aggregation, and low colloidal stability, resulting in premature drug release upon dilution (<0.1 mg/mL). To address these shortcomings, we developed HSA-polylactic acid (HSA-PLA) nanoparticles with enhanced negative surface charge (ζ = −27.4 mV) and improved colloidal stability to reduce the premature release of encapsulated PTX upon dilution (<0.01 mg/mL). In tumor models, comparative pharmacokinetics, biodistribution, and efficacy studies demonstrated that HSA-PLA (PTX) nanoparticles reduce premature drug release, resulting in greater tumor exposure (129 ± 3 vs. 90 ± 12 µg·h/g, p < 0.01) and superior antitumor efficacy compared with Abraxane. These improvements further suggest that optimization may require only a simple modification when guided by proper theoretical principles.

Silicone elastomers based on polydimethylsiloxane are biocompatible and non-biodegradable thermosetting polymers used in various drug delivery applications, including subdermal implants, vaginal rings, and intrauterine devices. Without exception, all marketed silicone elastomer drug delivery products provide sustained or controlled release of highly hydrophobic small drug molecules, since drug solubility in the silicone matrix is a prerequisite for molecular diffusion and release. We are interested in developing multipurpose silicone elastomer vaginal rings for local administration of metal ions—such as copper and zinc—for non-hormonal contraception and antimicrobial therapy. However, sustained/controlled release of metal ions from silicone elastomers containing metal nanopowders or metal salts is challenging due to their limited solubility in silicone. In this study, we assess the potential for enhancing the release of copper or zinc ions from silicone elastomer devices by co-formulating copper nanopowder, zinc nanopowder, copper sulfate, or zinc acetate with four common pharmaceutical excipients—gelatin, polyvinylpyrrolidone, sucrose, and hydroxypropyl methylcellulose. The study demonstrates that (i) copper/zinc nanopowders and salts can be successfully incorporated into addition-cure silicone elastomers, (ii) in vitro release of Cu2+/Zn2 ions from silicone elastomers loaded with divalent salts was ∼100 times greater compared to nanopowders; (iii) incorporation of gelatin, polyvinylpyrrolidone, sucrose and hydroxypropyl methylcellulose significantly enhanced the release of Cu2+/Zn2+ ions (up to ∼30-fold), and (iv) enhanced release was due to water absorption into the silicone elastomer devices, causing swelling of the devices to an extent proportional to the excipient loading.

ABSTRACT Extracellular vesicles (EVs) are emerging as versatile nanocarriers for targeted drug delivery and immune modulation. However, strategies that can induce antigen-specific immune tolerance remain limited, highlighting an unmet need for more precise and effective approaches. To address this challenge, we aimed to develop a modular EV-based system capable of inducing antigen-specific regulatory T cells (Tregs). In this study, we developed engineered antigen-presenting EVs (AP-EVs) that co-display peptide–major histocompatibility complex class II complexes (pMHCII), interleukin−2 (IL−2), and transforming growth factor-β (TGF-β) on their surface. These immunomodulatory molecules were anchored to the EV membrane via CD81 or milk fat globule-EGF factor 8 (MFG-E8) scaffolds to ensure stable and multivalent presentation. AP-EVs induced the differentiation of antigen-specific Tregs from naïve CD4⁺ T cells in vitro, and promoted their proliferation and expression of canonical regulatory markers, including CD25, CTLA−4, PD-L1, and LAG−3. In vivo, the combination of AP-EVs and mTOR inhibition with rapamycin significantly enhanced the generation of Foxp3⁺ Tregs in antigen-specific adoptive transfer models. The Tregs induced by AP-EVs in vitro exhibited suppressive function, highlighting the therapeutic potential of this system. Our findings establish a modular, cell-free EV platform for antigen-specific immune tolerance, with potential applications in the treatment of autoimmune and allergic diseases through targeted immune regulation.

Nowadays, pulmonary diseases (PDs) are among the leading causes of mortality worldwide. Conventional therapeutic approaches exhibit disappointing efficacies due to difficulty in drug delivery and systemic cytotoxicity. In recent years, novel formulations of therapeutic drugs rised as alternatives for clinical treatment. Among them, cell-derived drug delivery systems (CDDSs) have garnered attention for their potential in treating PDs. By harnessing the innate migratory capabilities, barrier-crossing potential, high biocompatibility, and substantial drug-loading capacity of cell derivatives, CDDSs offer a promising approach for PD treatment. However, there was no systemic report in summarizing CDDSs in PDs. In this review, We first examined the biological properties and therapeutic advantages of various CDDSs in the context of PDs, including red blood cells (RBCs), stem cells, platelets, macrophages, neutrophils, tumor cells, microalgae, extracellular vesicles (EVs) and biomimetic cell membrane. We then discussed common preparation strategies and different modification methods of CDDSs. Finally, we summarized the current therapeutic advancements of CDDSs in multiple PDs. We hope this review serves as a valuable reference for utilizing CDDSs in the treatment of PDs and other diseases.

Candida albicans is the most prominent conditional fungal pathogen, which can cause systemic candidiasis when an individual becomes immunocompromised. The widespread and long-term use of azoles like fluconazole (FLC) has led to a significant increase in drug resistance, posing substantial challenges to clinical treatment. In our previous study, benzyl isothiocyanate (BITC) was extracted from Carica papaya L. seed, and it exhibited a notable inhibitory effect against C. albicans. However, the application of BITC is restricted by its instability, poor water solubility, volatility, and easy degradation. This study aimed to prepare BITC-loaded nanostructured lipid carrier (BITC-NLC) to address these limitations of BITC and enhance antifungal efficacy in vitro and in vivo against C. albicans. The results of physicochemical properties showed that BITC-NLC had small particle size, good physical stability, and high encapsulation efficiency. In vitro, the antifungal effect of BITC-NLC was better than BITC against both sensitive and resistant C. albicans and better than FLC against resistant C. albicans. Moreover, in the in vivo experiment using systemic candidiasis mice model induced by resistant C. albicans, BITC-NLC was more remarkable than BITC and FLC in the increase of the survival rate and the splenic index, the reduction of the fungal burden, and the alleviation of the pathological damage. These findings may be attributed to the enhanced stability and sustained release of BITC. This study highlights the potential of BITC-NLC as a novel and effective formulation for the clinical treatment of drug-resistant C. albicans infections, thereby expanding the application scope of papaya.

Regulating inflammatory microglia presents a promising strategy for treating neurodegenerative and autoimmune disorders, yet effective therapeutic agents delivery to these cells remains a challenge. This study investigates modified lipid nanoparticles (LNP) for mRNA delivery to hyperactivated microglia, particularly those with pro-inflammatory characteristics, utilizing supervised machine learning (ML) classifiers. We developed and screened a library of 216 LNP formulations with varying lipid compositions, N/P ratios, and hyaluronic acid (HA) modifications. The transfection efficiency of eGFP mRNA was assessed in the BV-2 murine microglia cell line under different immunological states, including resting and activated conditions (LPS-activated and IL4/IL13-activated). ML-guided morphometric analysis tracked the phenotypes of various microglia subtypes before and after transfection. Four supervised ML classifiers were investigated to predict transfection efficiency and phenotypic changes based on LNP design parameters. The Multi-Layer Perceptron (MLP) neural network emerged as the best-performing model, achieving weighted F1-scores ≥0.8. While it accurately predicted responses from LPS-activated and resting cells, it struggled with IL4/IL13-activated cells. The MLP model was validated by predicting the performance of four unseen LNP formulations delivering eGFP mRNA to LPS-activated BV2 cells. HA-LNP2 emerged as optimal formulation for delivering target IL10 mRNA, effectively suppressing inflammatory phenotypes, evidenced by shifts in cell morphology, increased IL10 expression, and reduced TNF-α levels. We also evaluated HA-LNP2 on LPS-activated human iPSC-derived microglia, confirming its efficacy in modulating inflammatory responses. This study highlights the potential of tailored LNP design and ML techniques to enhance mRNA therapy for neuroinflammatory disorders by leveraging carrier’s immunogenic properties to modulate microglial responses.

Objective Antisense oligonucleotides (ASOs) have reached the clinic; however, they lack tissue specificity. Albumin is a plasma-abundant macromolecule that has been shown to accumulate in inflamed tissues. In this work, we have designed a recombinant human albumin (rHA)-based biomolecular assembly incorporating a DNase-resistant phosphorothioate-based complementary oligonucleotide (cODN) and an anti-ADAMTS5 ASO for potential delivery to inflamed sites. Ultrasound (US) was used to trigger ASO release from the assembly and enhance internalization into articular cartilage. Methods A phosphorothioate cODN was conjugated to rHA through a maleimide cross-linker after which, a therapeutic ADAMTS5-specific gapmer ASO was annealed to the cODN. ASO release was assessed after exposing the biomolecular assembly to different US conditions using an US-actuated medical needle operating at 32.2 kHz. Gene silencing efficiency of US-treated anti-ADAMTS5 ASO was assessed in human primary chondrocytes isolated from osteoarthritic patients. US-mediated ASO penetration into articular cartilage was assessed on ex vivo bovine articular cartilage. Results ASO release was observed after exposure to US waves in continuous mode conditions that did not compromise ASO gene silencing efficiency in human chondrocytes. Furthermore, US increased ASO internalization into bovine articular cartilage after 30 min of application without detrimental effects on chondrocyte viability. Conclusion A medical needle driven by continuous US waves at 32.2 kHz has the capability of disassembling a duplex oligonucleotide and enhancing released ASOs internalization into articular cartilage. This work offers the potential delivery and the local triggered release of ASOs at the surface of articular cartilage providing potential benefits for the treatment of diverse cartilage pathologies.

Rheumatoid arthritis (RA) is an inflammatory immune-triggered disease that causes synovitis, cartilage degradation, and joint injury. In nanotechnology, conventional liposomes were extensively investigated for RA. However, they frequently undergo rapid clearance, reducing circulation time and therapeutic efficacy. Additionally, their stability in the bloodstream is often compromised, resulting in premature drug release. The current review explores the potential of targeted liposomal-based nanosystems in the treatment of RA. It highlights the pathophysiology of RA, explores selective targeting sites, and elucidates diverse mechanisms of novel liposomal types and their applications. Furthermore, the targeting strategies of pH-sensitive, flexible, surface-modified, PEGylated, acoustic, ROS-mediated, and biofunctionalized liposomes are addressed. Targeted nanoliposomes showed potential in precisely delivering drugs to CD44, SR-A, FR-β, FLS, and toll-like receptors through the high affinity of ligands. In vitro studies interpreted stable release profiles and improved stability. Ex vivo studies on skin demonstrated that ultradeformable and glycerol-conjugated liposomes enhanced drug penetrability. In vivo experiments for liposomal types in the arthritis rat model depicted remarkable efficacy in reducing joint swelling, pro-inflammatory cytokines, and synovial hyperplasia. In conclusion, these targeted liposomes represented a significant leap forward in drug delivery, offering effective therapeutic options for RA. In the future, integrating these advanced liposomes with artificial intelligence, immunotherapy, and precision medicine holds great promise.

Silicosis represents a formidable occupational lung pathology precipitated by the pulmonary assimilation of respirable crystalline silica particulates. This condition engenders a cascade of cellular oxidative stress via the activation of bioavailable silica, culminating in the generation of reactive oxygen species (ROS). Such oxidative mechanisms lead to irrevocable pulmonary impairment. Contemporary scholarly examinations have underscored the substantial antioxidative efficacy of platinum nanoparticles (PtNPs), postulating their utility as an adjunct therapeutic modality in silicosis management. The physicochemical interaction between PtNPs and silica demonstrates a propensity for adsorption, thereby facilitating the amelioration and subsequent pulmonary clearance of silica aggregates. In addition to their detoxifying attributes, PtNPs exhibit pronounced anti-inflammatory and antioxidative activities, which can neutralize ROS and inhibit macrophage-mediated inflammatory processes. Such attributes are instrumental in attenuating inflammatory responses and forestalling subsequent lung tissue damage. This discourse delineates the interplay between ROS and PtNPs, the pathogenesis of silicosis and its progression to pulmonary fibrosis, and critically evaluates the potential adjunct role of PtNPs in the therapeutic landscape of silicosis, alongside a contemplation of the inherent limitations associated with PtNPs application in this context.