Tailored lipid nanoparticles (LNPs)-mediated small interfering RNA (siRNA) nanomedicines show promise in treating liver disease, such as acute liver injury (ALI) and non-alcoholic steatohepatitis (NASH). However, constructing LNPs that address biosafety concerns, ensure efficient delivery, and target specific hepatic subcellular fractions has been challenging. To evade above obstacles, we develop three novel self-degradable "gemini-like" ionizable lipids (SS-MA, SS-DC, SS-MH) by incorporating disulfide bonds and modifying the length of ester bond and tertiary amino head. Our findings reveal that the disulfide-bond-bridged LNPs exhibit reduction-responsive drug release, improving both biosafety and siRNA delivery efficiency. Furthermore, the distance of ester bond and tertiary amino head significantly influences the LNPs' pK _a, thereby affecting endosomal escape, hemolytic efficiency, absorption capacity of ApoE, uptake efficiency of hepatocytes and liver accumulation. We also develop the modified-mannose LNPs (M-LNP) to target liver macrophages specifically. The optimized M-MH_LNP@TNFα exhibits potential in preventing ALI by decreasing tumor necrosis factor α (TNFα) levels in the macrophages, while MH_LNP@DGAT2 could treat NASH by selectively degrading diacylglycerol O-acyltransferase 2 (DGAT2) in the hepatocytes. Our findings provide new insights into developing novel highly effective and low-toxic "gemini-like" ionizable lipids for constructing LNPs, potentially achieving more effective treatment for hepatic diseases.

Cells and exosomes derived from them are extensively used as biological carrier systems. Cells demonstrate superior targeting specificity and prolonged circulation facilitated by their rich array of surface proteins, while exosomes, due to their small size, cross barriers and penetrate tumors efficiently. However, challenges remain, cells' large size restricts tissue penetration, and exosomes have limited targeting accuracy and short circulation times. To address these challenges, we developed a novel concept termed exosomal spheres. This approach involved incorporating platelet-derived exosomes shielded with phosphatidylserine (PS) and linked via pH-sensitive bonds for drug delivery applications. The study demonstrated that, compared with exosomes, the exosomal spheres improved blood circulation through the upregulation of CD47 expression and shielding of phosphatidylserine, thereby minimizing immune clearance. Moreover, the increased expression of P-selectin promoted adhesion to circulating tumor cells, thereby enhancing targeting efficiency. Upon reaching the tumor site, the hydrazone bonds of exosome spheres were protonated in the acidic tumor microenvironment, leading to disintegration into uniform-sized exosomes capable of deeper tumor penetration compared to platelets. These findings suggested that exosome spheres addressed the challenges and offered significant potential for efficient and precise drug delivery.

[This corrects the article DOI: 10.1016/j.apsb.2021.08.008.].

Substantial progress in the use of chemo-photodynamic nano-drug delivery systems (nano-DDS) for the treatment of the malignant breast cancer has been achieved. The inability to customize precise nanostructures, however, has limited the therapeutic efficacy of the prepared nano-DDS to date. Here, we report a structurally defined tandem-responsive chemo-photosensitive co-nanoassembly to eliminate primary breast tumor and prevent lung metastasis. This both-in-one co-nanoassembly is prepared by assembling a biocompatible photosensitive derivative (pheophorbide-diphenylalanine peptide, PPA-DA) with a hypoxia-activated camptothecin (CPT) prodrug [(4-nitrophenyl) formate camptothecin, N-CPT]. According to computational simulations, the co-assembly nanostructure is not the classical core-shell type, but consists of many small microphase regions. Upon exposure to a 660 nm laser, PPA-DA induce high levels of ROS production to effectively achieve the apoptosis of normoxic cancer cells. Subsequently, the hypoxia-activated N-CPT and CPT spatially penetrate deep into the hypoxic region of the tumor and suppress hypoxia-induced tumor metastasis. Benefiting from the rational design of the chemo-photodynamic both-in-one nano-DDS, these nanomedicines exhibit a promising potential in the inhibition of difficult-to-treat breast tumor metastasis in patients with breast cancer.

Liposomes have made remarkable achievements as drug delivery vehicles in the clinic. Liposomal products mostly benefited from remote drug loading techniques that succeeded in amphipathic and/or ionizable drugs, but seemed impracticable for nonionizable and poorly water-soluble therapeutic agents, thereby impeding extensive promising drugs to hitchhike liposomal vehicles for disease therapy. In this study, a series of weak acid drug derivatives were designed by a simplistic one step synthesis, which could be remotely loaded into liposomes by pH gradient method. Cabazitaxel (CTX) weak acid derivatives were selected to evaluate regarding its safety profiles, pharmacodynamics, and pharmacokinetics. CTX weak acid derivative liposomes were superior to Jevtana® in terms of safety profiles, including systemic toxicity, hematological toxicity, and potential central nerve toxicity. Specifically, it was demonstrated that liposomes had capacity to weaken potential toxicity of CTX on cortex and hippocampus neurons. Significant advantages of CTX weak acid derivative-loaded liposomes were achieved in prostate cancer and metastatic cancer therapy resulting from higher safety and elevated tolerated doses.

A commercial albumin-bound paclitaxel nano-formulation has been considered a gold standard against breast cancer. However, its application still restricted unfavorable pharmacokinetics and the immunogenicity of exogenous albumin carrier. Herein, we report an albumin-bound tumor redox-responsive paclitaxel prodrugs nano-delivery strategy. Using diverse linkages (thioether bond and disulfide bond), paclitaxel (PTX) was conjugated with an albumin-binding maleimide (MAL) functional group. These pure PTX prodrugs could self-assemble to form uniform and spherical nanoparticles (NPs) in aqueous solution without any excipients. By immediately binding to blood circulating albumin after intravenous administration, NPs are rapidly disintegrated into small prodrug/albumin nanoaggregates

Drug stability is closely related to drug safety and needs to be considered in the process of drug production, package and storage. To investigate the stability of epalrestat, a carboxylic acid derivative, a reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed in this study and applied to analyzing the degradation kinetics of epalrestat in aqueous solutions in various conditions, such as dif-ferent pH, temperatures, ionic strengths, oxidation and irradiation. The calibration curve was A=1.6 × 105C–1.3 × 103 (r=0.999) with the liner range of 0.5–24 μg/mL, the intra-day and inter-day precision was less than 2.0%, as was the repeatibility. The average accuracy for different concentrations was more than 98.5%, indicating that perfect recoveries were achieved. Degradation kinetic parameters such as degradation rate constants (k), activation energy (Ea) and shelf life (t0.9) under different conditions were calculated and discussed. The results indicated that the degradation behavior of epalrestat was pH-dependent and the stability of epalrestat decreased with the rised irradiation and ionic strength;however, it was more stable in neutral and alkaline conditions as well as lower temperatures. The results showed that the degradation kinetics of epalrestat followed first-order reaction kinetics. Furthermore, the degradation products of epalrestat under stress conditions were identified by UHPLC-PDA-MS/MS, with seven degradation products being detected and four of them being tentatively identified.

Prodrug nanoassemblies, which can refrain from large excipients, achieve higher drug loading and control drug release, have been placed as the priority in drug delivery system. Reasoning that glutathione (GSH) and reactive oxygen species (ROS) are highly upgraded in tumor tissues which makes them attractive targets for drug delivery system, we designed and synthetized a novel prodrug which utilized mono thioether bond as a linker to bridge linoleic acid (LA) and docetaxel (DTX). This mono thioether-linked conjugates (DTX-S-LA) could self-assemble into nanoparticles without the aid of much excipients. The mono thioether endowed the nanoparticles redox sensitivity resulting in specific release at the tumor tissue. Our studies demonstrated that the nanoassemblies had uniform particle size, high stability and fast release behavior. DTX-S-LA nanoassemblies outperformed DTX solution in pharmacokinetic profiles for it had longer circulation time and higher area under curve (AUC). Compared with DTX solution, the redox dual-responsive nanoassemblies had comparable cytotoxic activity. Besides, the antitumor efficacy was evaluated in mice bearing 4T1 xenograft. It turned out this nanoassemblies could enhance anticancer efficacy by increasing the dose because of higher tolerance. Overall, these results indicated that the redox sensitivity nanoassemblies may have a great potential to cancer therapy.

Hyaluronic acid (HA) is a natural ligand of tumor-targeted drug delivery systems (DDS) due to the relevant CD44 receptor overexpressed on tumor cell membranes. However, other HA receptors (HARE and LYVE-1) are also overexpressing in the reticuloendothelial system (RES). Therefore, polyethylene glycol (PEG) modification of HA-based DDS is necessary to reduce RES capture. Unfortunately, pegylation remarkably inhibits tumor cellular uptake and endosomal escapement, significantly compromising the antitumor efficacy. Herein, we developed a Dox-loaded HA-based transformable supramolecular nanoplatform (Dox/HCVBP) to overcome this dilemma. Dox/HCVBP contains a tumor extracellular acidity-sensitive detachable PEG shell achieved by a benzoic imine linkage. The and investigations further demonstrated that Dox/HCVBP could be in a "stealth" state at blood stream for a long circulation time due to the buried HA ligands and the minimized nonspecific interaction by PEG shell. However, it could transform into a "recognition" state under the tumor acidic microenvironment for efficient tumor cellular uptake due to the direct exposure of active targeting ligand HA following PEG shell detachment. Such a transformative concept provides a promising strategy to resolve the dilemma of natural ligand-based DDS with conflicting two processes of tumor cellular uptake and nonspecific biodistribution.

This study investigated the protection against the ND in chickens by a recombinant DNA vaccine. A plasmid vector encoding NDV F protein, which is reqired for virus cell fusion and is important for vaccine induced immunity, was used as a model to study how DNA vaccines may be modulated by the simulaneous expression of chicken IL-2. The NDV D26 strain F gene with CMV promotor and BGH polyA signal sequence was amplified by PCR from eukaryotic plasmid pcDNA-F, which contains the full-length NDV F gene, and clond into reconstructed eukaryotic plasmid pcDNA-IL2, which contains chicken IL-2 gene. Restriction endonuclease cleavage and PCR amplification showed that a bicistronic plasmid encoding NDV F gene and chicken IL-2 separately was successfully constructed. Two-week-old SPF chickens were intramuscularly innoculated the recombinant plasmid. Antibody and lymphocyte proliferative assay showed that the humoral and cellular immunity of chickens vaccinated the recombinant plasmid greatly increased compared with those innoculated only plasmid expressing NDV F protein. Challenged with the lethal dose of NDV F48E9 strain, 72% chickens vaccinated recombinant plasmid were survived, and 30% chickens vaccinated plasmid expressing F protein were survived. These results proved the adjuvant effect of chicken IL-2, and further showed that the efficacy of a DNA vaccine can be greatly improved by simultaneous expression of IL-2.