Mechanism of mitochondrial oxidative phosphorylation disorder in male infertility.

ABSTRACT: Male infertility has become a global concern, accounting for 20-70% of infertility. Dysfunctional spermatogenesis is the most common cause of male infertility; thus, treating abnormal spermatogenesis may improve male infertility and has attracted the attention of the medical community. Mitochondria are essential organelles that maintain cell homeostasis and normal physiological functions in various ways, such as mitochondrial oxidative phosphorylation (OXPHOS). Mitochondrial OXPHOS transmits electrons through the respiratory chain, synthesizes adenosine triphosphate (ATP), and produces reactive oxygen species (ROS). These mechanisms are vital for spermatogenesis, especially to maintain the normal function of testicular Sertoli cells and germ cells. The disruption of mitochondrial OXPHOS caused by external factors can result in inadequate cellular energy supply, oxidative stress, apoptosis, or ferroptosis, all inhibiting spermatogenesis and damaging the male reproductive system, leading to male infertility. This article summarizes the latest pathological mechanism of mitochondrial OXPHOS disorder in testicular Sertoli cells and germ cells, which disrupts spermatogenesis and results in male infertility. In addition, we also briefly outline the current treatment of spermatogenic malfunction caused by mitochondrial OXPHOS disorders. However, relevant treatments have not been fully elucidated. Therefore, targeting mitochondrial OXPHOS disorders in Sertoli cells and germ cells is a research direction worthy of attention. We believe this review will provide new and more accurate ideas for treating male infertility.

A fully biodegradable spherical nucleic acid nanoplatform for self-codelivery of doxorubicin and miR122 for innate and adaptive immunity activation.

Facile construction of a fully biodegradable spherical nucleic acid (SNA) nanoplatform is highly desirable for clinical translations but remains rarely explored. We developed herein the first polycarbonate-based biodegradable SNA nanoplatform for self-codelivery of a chemotherapeutic drug, doxorubicin (DOX), and a human liver-specific miR122 for synergistic chemo-gene therapy of hepatocellular carcinoma (HCC). Ring-opening polymerization (ROP) of a carbonate monomer leads to a well-defined polycarbonate backbone for subsequent DOX conjugation to the pendant side chains via acidic pH-cleavage Schiff base links and miR122 incorporation to the chain termini via click coupling, affording an amphiphilic polycarbonate-DOX-miR122 conjugate, PBis-Mpa30-DOX-miR122 that can self-assemble into stabilized SNA. Besides the desired biodegradability, another notable merit of this nanoplatform is the use of miR122 not only for gene therapy but also for enhanced innate immune response. Together with the ICD-triggering effect of DOX, PBis-Mpa30-DOX-miR122 SNA-mediated DOX and miR122 codelivery leads to synergistic immunogenicity enhancement, resulting in tumor growth inhibition value (TGI) of 98.1 % significantly higher than those of the groups treated with only drug or gene in a Hepa1-6-tumor-bearing mice model. Overall, this study develops a useful strategy toward biodegradable SNA construction, and presents a drug and gene-based self-codelivery SNA with synergistic immunogenicity enhancement for efficient HCC therapy. STATEMENT OF SIGNIFICANCE: Facile construction of a fully biodegradable SNA nanoplatform is useful for in vivo applications but remains relatively unexplored likely due to the synthetic challenge. We report herein construction of a polycarbonate-based SNA nanoplatform for co-delivering a chemotherapeutic drug, DOX, and a human liver-specific miR-122 for synergistic HCC treatment. In addition to the desired biodegradability properties, this SNA nanoplatform integrates DOX-triggered ICD and miR-122-enhanced innate immunity for simultaneously activating adaptive and innate immunities, which leads to potent antitumor efficiency with a TGI value of 98.1 % in a Hepa1-6-tumor-bearing mice model.

Optimized aptamer functionalization for enhanced anticancer efficiency in vivo.

Nucleic acid aptamers (Apt) are RNA or DNA fragments that can bind specifically to a target molecule or to a target substrate with great affinity, thus has attracted great attention for diagnosis and treatment of various malignant diseases. Two primary strategies reported for efficient incorporation of Apt into a nanocarrier include physical encapsulation via electrostatic interactions and chemical conjugation via covalent bonds. Generally, physical encapsulation offers an easier approach for Apt functionalization than covalent bonding that involves sophisticated chemical design as well as synthesis and purification procedures. However, the effect of Apt's incorporation strategies on the property and performance of Apt-functionalized nanocarriers, to our knowledge, remains unclear, which clearly hampers the biomedical applications and potential clinical translations of Apt-decorated delivery systems. To clarify this critical issue toward better performance of Apt for biomedical applications, an Apt moiety with a specific targeting property to liver cancer cells was introduced to a previously fabricated polymeric prodrug, chitosan-5-fluorouracil-1-acetic acid (CS-FU) via either an amide link or electrostatic interactions to afford two types of Apt-functionalized polymeric prodrugs, i.e., Apt/CS-FU and Apt-CS-FU with an equivalent amount of incorporated Apt, respectively. The in vivo and in vitro anti-tumor efficacy and targeting properties of these two Apt-functionalized polymeric prodrugs were investigated and further compared in detail. Interestingly, the two self-assembled micelles showed almost identical in vitro targeting and antitumor efficiency, but Apt-CS-FU mediated 1.5-fold greater tumor inhibition rate (TIR) than Apt/CS-FU in murine tumor models. The better performance of Apt-CS-FU than that of Apt/CS-FU was substantially attributed to the smaller size of Apt-CS-FU than that of Apt/CS-FU in the presence of serum for prolonged in vivo circulation. The first disclosed Apt incorporation strategy effects on the performance and property of Apt-decorated nanocarriers is believed to promote rational design and future clinical translations of Apt-functionalized nanoplatforms with greater therapeutic efficiency.

A ROS-Responsive Liposomal Composite Hydrogel Integrating Improved Mitochondrial Function and Pro-Angiogenesis for Efficient Treatment of Myocardial Infarction.

Mitochondrial dysfunction of cardiomyocytes (CMs) has been identified as a significant pathogenesis of early myocardial infarction (MI). However, only a few agents or strategies have been developed to improve mitochondrial dysfunction for the effective MI treatment. Herein, a reactive oxygen species (ROS)-responsive PAMB-G-TK/4-arm-PEG-SG hydrogel is developed for localized drug-loaded liposome delivery. Notably, the liposomes contain both elamipretide (SS-31) and sphingosine-1-phosphate (S1P), where SS-31 acts as an inhibitor of mitochondrial oxidative damage and S1P as a signaling molecule for activating angiogenesis. Liposome-encapsulated PAMB-G-TK/4-arm-PEG-SG hydrogels demonstrate myocardium-like mechanical strength and electrical conductivity, and ROS-sensitive release of SS-31 and S1P-loaded liposomes. Further liposomal release of SS-31, which can target cytochrome c in the mitochondrial inner membrane of damaged CMs, inhibits pathological ROS production, improving mitochondrial dysfunction. Meanwhile, S1P released from the liposome induces endothelial cell angiogenesis by activating the S1PR1/PI3K/Akt pathway. In a rat MI model, the resulting liposomal composite hydrogel improves cardiac function by scavenging excess ROS, improving mitochondrial dysfunction, and promoting angiogenesis. This study reports for the first time a liposomal composite hydrogel that can directly target mitochondria of damaged CMs for a feedback-regulated release of encapsulated liposomes to consume the overproduced pathological ROS for improved CM activity and enhanced MI treatment.

Multicyclic topology-enhanced anticancer drug delivery.

Inspired by the biological use of a combination of precision and self-assembly to achieve exquisite control and diversity from 20 natural amino acids, there is considerable scope for the development of synthetic precision materials with complex architecture that can access advanced function for biomedical applications. Single cyclic polymers (SCPs) have been shown to offer different and often better performance compared to their linear analogues. Because multicyclic topology in nature offers enhanced effects relative to single cyclization, we hypothesize that multicyclic polymers (MCPs) would access unique features compared to SCPs. However, there are currently quite limited ways to efficiently synthesize MCPs and to precisely modulate the valency of cyclic units. In this work, we report for the first time a straightforward and robust strategy to synthesize MCPs with controllable valency via facile one-pot statistical reversible addition-fragmentation chain transfer (RAFT) copolymerization. We use this strategy to synthesize biocompatible MCPs based on the most classic and important biocompatible polymers of oligo (ethylene glycol) (OEG) and cyclic poly(ε-caprolactone) (cPCL), which can further self-assemble into well-defined nanostructures. We then apply these MCP-based formulations as drug delivery vehicles and demonstrate greater colloidal stability with a low critical micelle concentration (CMC) of 80.3 nM, larger drug loading capacity, higher cellular uptake efficiency, more tumor accumulation, and increased anti-tumor efficacy in murine tumor models compared to SCP-based analogues. We believe this cumulative work demonstrating facile synthesis of MCPs and demonstration of multicyclic topology-enhanced anti-cancer efficiency in vivo provides key technologies and concepts to the burgeoning field of cyclic topology-derived biomaterials.

Efficacy and Mechanism of Quercetin in the Treatment of Experimental Colitis Using Network Pharmacology Analysis.

Quercetin, a flavonoid that is present in vegetables and fruits, has been found to have anti-inflammatory effects. However, the mechanism by which it inhibits colitis is uncertain. This study aimed to explore the effect and pharmacological mechanism of quercetin on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC). Mice were given a 4% (w/v) DSS solution to drink for 7 days, followed by regular water for the following 5 days. Pharmacological mechanisms were predicted by network pharmacology. High-throughput 16S rDNA sequencing was performed to detect changes in the intestinal microbiota composition. Enzyme-linked immunosorbent assay and western blotting were performed to examine the anti-inflammatory role of quercetin in the colon. Quercetin attenuated DSS-induced body weight loss, colon length shortening, and pathological damage to the colon. Quercetin administration modulated the composition of the intestinal microbiota in DSS-induced mice and inhibited the growth of harmful bacteria. Network pharmacology revealed that quercetin target genes were enriched in inflammatory and neoplastic processes. Quercetin dramatically inhibited the expression of phosphorylated protein kinase B (AKT) and phosphatidylinositol 3-kinase (PI3K). Quercetin has a role in the treatment of UC, with pharmacological mechanisms that involve regulation of the intestinal microbiota, re-establishment of healthy microbiomes that favor mucosal healing, and the inhibition of PI3K/AKT signaling.

Fabrication and characterization of a novel self-assembling micelle based on chitosan cross-linked pectin-doxorubicin conjugates macromolecular pro-drug for targeted cancer therapy.

Cancer is one of the leading causes of morbidity and mortality worldwide. Doxorubicin is one of the most effective anticancer drugs approved by FDA. However, like all the other anticancer drugs, the efficacy of DOX is associated with high systemic toxicity to healthy tissues. In this study, chitosan cross-linked pectin-doxorubicin conjugates macromolecular pro-drug (CS-PDC-M) was prepared to enhance the therapeutic effects on liver cancer. CS-PDC-M was characterized in terms of size, size distribution, zeta potential, scanning electron microscope (SEM) and drug loading content. The CS-PDC-M achieved prolonged releasing ability was demonstrated by the in vitro drug release and in vitro cellular uptake assay. Biocompatibility of CS-PDC-M was screened by hemolysis activity examination, BSA adsorption test and cell viability evaluation in endothelial cells and LO2 cells. The CS-PDC-M achieved significantly high antitumor efficiency and targeting efficiency, which was demonstrated by the in vitro MTT assay and cellular targeting assay toward HepG2 cells, MCF-7 cells and A549 cells. The in vivo antitumor efficacy of CS-PDC-M was studied in athymic BALB/c nude mice bearing HepG2 cell xenografts. The organ damage assays of CS-PDC-M was studied in SD rats. Compared with that of free DOX and PDC-M, the CS-PDC-M exhibited higher antitumor efficacy and lower toxicity, implying that CS-PDC-M is a highly promising drug delivery system for hepatocellular carcinoma treatment.