Lysosomes are intracellular organelles with lysosomal or digestive functions which contain various acid-dependent enzymes that are responsible for the recycling and degradation of intracellular substances. pH changes in lysosomes can reduce the activity of various enzymes, impairing the cell′s regulatory capacity and ultimately leading to apoptosis or pyroptosis. Therefore, monitoring lysosomal pH values is valuable for investigating alterations in intracellular physiological and pathological processes. This study developed a novel pH-responsive near-infrared (NIR) fluorescent probe targeting lysosomes, named piperazine-croconic acid-piperazine (PCP). This probe was formed by connecting the electron-donating group piperazine to both ends of croconic acid. The π-conjugated system, featuring a five-membered ring structure, endowed the probe with excellent stability and resistance to photobleaching. The tertiary amine moiety of piperazine, serving as a lysosome-targeting group, produced reversible protonation/deprotonation under varying pH conditions as result of exhibiting pH-responsive characteristics. The synthesized PCP demonstrated excellent NIR fluorescence performance, making it suitable for fluorescence imaging of lysosomal pH values in living cells. Both solution and intracellular experiments confirmed that PCP exhibited good biocompatibility and pH-responsive characteristics. Additionally, its symmetrical structure and molecular rigidity contributed to its excellent resistance to photobleaching. This study employed PCP probes to detect the pH values of the lysosomes, offering potential avenues for the treatment and prevention of diseases associated with lysosomal dysfunction.

New dressings represent a hot topic at the intersection of pharmacy, materials science, and medicine. The development of dressings with excellent biocompatibility, pharmacological activity, and mechanical properties is a new trend in this field. This study utilizes wood-based materials with inherent biocompatibility as the substrate. The ice crystal-induced phase separation method is employed to remove the tough lignin components, resulting in a three-dimensional micro-nano network structure of cellulose-hemicellulose matrix. Molecular injection is used to embed natural bioactive molecules tannin and auxiliary molecules polyvinyl alcohol in the matrix. Through multiple dynamic hydrogen bonding interactions, a novel dressing (de-lignin gel with PVA added, PLG) with both mechanical strength and biological activity is prepared. Various technical methods are employed to characterize the structure of PLG and investigate its bioactive functions. The results indicate that the designed PLG synthesis route is reasonable. The successfully obtained PLG exhibits excellent anisotropic mechanical strength and fatigue resistance (energy dissipation of 22.8 kPa·mm^-1). It also features a low linear expansion rate, outstanding adhesion capability, and anti-swelling properties. Antimicrobial experiments show that PLG exhibits antibacterial rates of 74.3% and 77.6% against Staphylococcus aureus and Escherichia coli, respectively. This indicates its broad-spectrum contact antibacterial effect. The radical scavenging rate of PLG reached 95.88%. Combined with mouse wound healing experiments, it was confirmed that PLG effectively reduces inflammatory responses through a dual antioxidant-antibacterial mechanism. The multi-layered structural design and cross-scale performance exploration of the dressing provide meaningful references for developing novel dressings that integrate mechanical adaptability, bioactivity, and multi-functional properties. The animal experiments were approved by the Laboratory Animal Ethics Committee of Zhejiang A & F University (No. ZAFUAC202514). All experiments were carried out strictly in accordance with relevant guiding principles and regulations.

Ranked second and fourth respectively in incidence rate and mortality rate among various cancers, breast cancer is characterized by strong invasion, high recurrence, poor prognosis and a lack of effective treatment, rendering the quality of life and the survival time of patients unsatisfactory. Herein, we designed a dual-response shape-transformable nanomicelle consisted of two amphipathy chains of different length, within which the chemotherapeutic agent paclitaxel (PTX) is encapsulated in the hydrophobic cavity. Based on it a combined therapy of photodynamic therapy, immunotherapy and chemotherapy was developed to augment the accumulation of therapeutic drugs in breast cancer tissues and treating efficacy. Entered in tumour microenvironment (TME), the shape transformation of micelles would be triggered by reactive oxygen species (ROS) and matrix metalloproteinase-2 (MMP-2), so as to increase the retention of the photosensitizer pyropheophorbide-a (Ppa) in tumours and release PTX and D-type programmed cell death ligand 1 (PD-L1) peptide antagonist (dPPA) concurrently, thus addressing the incompatibility of long blood circulation time, tumor penetration and retention. Under the irradiation of near infrared light, ROS produced by Ppa brought about stronger killing of cancer cells, activation of host immunity and promotion of ROS response. The dual-responsive group PTX@DTPD-PPP, along with two single-responsive groups PTX@DTPD-PRP and PTX@DPD-PPP and non-responsive group PTX@DPD-PRP were initially synthesized and characterized. Through cellular uptake experiment, light-responsive ROS generation experiment, cytotoxicity test, migration and invasion test and so forth, we proved the enhancement in both drug delivery and treating effect of dual-responsive formation. These findings demonstrate that PTX@DTPD-PPP is fulfilled with an uniform particle size (144 ± 1.3 nm) and a negative surface (-6.8 ± 0.9 mV), as well as the transformation responsiveness in 4 h within in vitro experiments. Both the drug accumulation and cellular toxicity of dual-responsive group are prominently increased in contrast with free Ppa, free PTX as well as other formations, laying a foundation for the sequent in-vivo studies.

Aloesone synthase (ALS), as a type Ⅲ polyketide synthase, plays an important role during the biosynthesis of diverse and active polyketide basic structural frameworks. In order to explore the expression pattern and function of RoALS2 in Rheum officinale, real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-qPCR), prokaryotic expression, and other techniques were used to analyze the expression pattern, in vitro protein expression, etc. of RoALS2 based on the previous transcriptome data. The overall results showed that the total length of the RoALS2 gene was 1 176 bp in size, encoding 391 amino acids, without signal peptides or transmembrane domains. Through evolutionary analysis and comparison, it was found that the RoALS2 is closely related to the ALS protein of Polygonum cuspidatum and R. palmatum. The RT-qPCR results showed that the relative expression level of RoALS2 in the roots and rhizomes of R. officinale increased first and then decreased with the change of growth years. The relative expression level was highest in the roots and rhizomes of two-year-old samples. The expression patterns of RoALS2 under different hormones' treatment were also different, and the overall trend was first upregulated, then downregulated, and then upregulated again. RoALS2 could respond to be upregulated by MeJA and SA treatments, but down-regulated by ABA and ethephon significantly. RoALS2 was then constructed into prokaryotic expression vectors pET-28a(+) and pGEX6p-1 respectively, and transformed into BL21 (DE3) competent, both of which showed successfully induction of the target fusion proteins. However, the pET-28a(+)-RoALS2 strain could be detected of the target band in the supernatant and the soluble protein was also obtained, whereas pGEX6P-1-RoALS2 recombinant protein existed in the form of inclusion bodies in the precipitate. The research results lay a solid foundation for further function characterization of the gene and elucidation of the molecular mechanisms of quality development of rhubarb from R. officinale.

Capsular polysaccharides and lipopolysaccharides are crucial bacterial virulence factors and key vaccine antigen targets. Over the past century, the development of bacterial polysaccharide-based vaccines has significantly advanced global efforts to prevent bacterial infections. This review outlines the historic milestones of bacterial polysaccharide vaccines, with an emphasis on the development and application of capsular polysaccharide-based vaccines against three human pathogens: Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Moreover, this article summarizes the protective mechanisms and perspectives of polysaccharide-based vaccines.

There exist significant changes in glycosyltransferase expression during tumorigenesis, which leads to the unique sugar chain structural characteristics of glycoproteins on the surface of tumor cells compared to normal cells, namely highly truncated sugar chains. These aberrant glycosylated products are called tumor-associated carbohydrate antigens (tumor-associated carbone antigens, TACAs). As an important molecular marker of malignant tumors, TACAs not only participate in the regulation of tumor occurrence, development, invasion and metastasis of tumors, but also play a key role in tumor immune escape. Thus, targeting abnormally glycosylated proteins or peptides on tumors have become one of most important anti-tumor drug development strategies. However, it is difficult to isolate glycoproteins from natural sources, and it is still challenging to synthesize complex glycoproteins or glycopeptides by chemical methods. This review summarizes the progress of glycopeptide anti-tumor vaccine synthesized by chemical methods in recent years, in order to provide theoretical basis and technical reference for the research and development of glycopeptide anti-tumor vaccine in the future.

Glycoconjugate vaccines are essential tools for preventing bacterial infectious diseases. Currently licensed glycoconjugate vaccines are produced through a stepwise process that involves the extraction of native polysaccharide antigens, purification of carrier proteins, and subsequent in vitro chemical conjugation. In recent years, the rapid advancement of emerging technologies such as synthetic biology has driven the development of innovative strategies for designing and manufacturing glycoconjugate vaccines. This review highlights progress in two representative technologies: protein glycan coupling technology (PGCT) and cell-free glycoprotein synthesis (CFGpS). It also briefly explores additional emerging approaches in glycoconjugate vaccine development, including generalized modules for membrane antigens (GMMA), semi-synthetic glycoconjugate vaccines, non-covalent coupling strategies, and click chemistry-based conjugation using non-natural amino acids. Looking ahead, advancements in artificial intelligence (AI) are expected to accelerate the computational design and engineering of oligosac-charyltransferases and carrier proteins, ultimately improving the immunogenicity and manufacturing efficiency of next-generation glycoconjugate vaccines.

Carbohydrate and glycopeptide vaccines have shown great promise in tumor prevention and treatment. However, their relatively low immunogenicity remains a significant challenge. To address this, adjuvants are commonly employed to enhance immune responses against specific antigens. Despite their widespread use, conventional adjuvants still face several limitations, including limited immune stimulation and potential safety concerns associated with molecular diffusion. A promising strategy to overcome these challenges is the incorporation of built-in adjuvants, which promotes adjuvants to augment their immunostimulatory effect. This review highlights the application of various immune agonists as built-in adjuvants to enhance vaccine immunogenicity, including Toll-like receptor (TLR) agonists, invariant natural killer T (iNKT) cell agonists, stimulator of interferon genes (STING) agonists, nucleotide-binding oligomerization domain-like receptors (NLR) agonists, and C-type lectin receptor (CLR) agonists. By summarizing recent advancements in this field, we provide valuable insights into the development of more effective and safer carbohydrate vaccines.

This study aims to evaluate the immunogenicity and safety of the 20-valent pneumococcal conjugate vaccine (PCV20). Different evaluation models were established using ICR mice and SD rats to assess the immunogenicity and toxic reactions. The results showed that the immunogenicity test in mice demonstrated good immunogenicity for three batches of the 20-valent pneumococcal conjugate vaccine after three doses. The immunogenicity test in rats showed that the vaccine induced antibodies against 20 pneumococcal serotypes within 2 weeks after the first dose and maintained a certain level for 3 weeks after the final dose, indicating good immune persistence. The vaccine was administered to mice at the maximum dosage without any significant toxic reactions observed. The repeated-dose safety test in rats showed local irritation and pathological changes at the injection site, which were alleviated during the recovery period. No significant toxic reactions were observed at the end of the dosing period and the recovery period. Studies have shown that the novel 20-valent pneumococcal conjugate vaccine exhibits good immunogenicity and safety in mouse and rat models. The use of all experimental animals has been approved by the Ethics Committee of Laboratory Animal of Beijing Minhai Biological Technology Co. Ltd. (No. 202309, 202311).

O-Antigens is the outermost component of bacterial lipopolysaccharide (LPS). Their structural complexity and diversity are essential for bacterial immune evasion, pathogenicity, and bacteria-host interactions. In this study, the O-antigen of lipopolysaccharide from Escherichia coli strain EPEC080 was extracted and purified. The chemical structure of the O-antigen was determined by a combination of various analytical methods, including molecular weight determination, monosaccharide composition analysis, infrared spectrum and nuclear magnetic resonance analysis. The O-antigen with an average molecular weight of 14.3 kDa was determined to consist of a pentasaccharide repeating unit: →4)-[α-D-GalpNAc-(1→3)]-α-L-Rhap-(1→2)-[β-D-GalpNAc-(1→3)]-α-L-Rhap-(1→2)-α-L-Rhap-(1→. Notably, this structure is different from those of known E. coli LPS O-antigens, indicating that strain EPEC080 represents a novel E. coli serotype. The structural identification of this O-antigen provides a foundation for further investigation of the pathogenesis of enteropathogenic E. coli and development of prophylaxis and treatment methods against the related diseases.