Collagen is the main constituent of gelatinous Chinese medicine, with deer hide gelatin (Cervi Corii Colla, DHG) made from deer hide (DH) through a complex thermal and high-pressure processing procedure. During this procedure some amino acids in collagen undergo hydroxylation and deamidation. In the present study, comparative analysis of proteins and peptides in DH and DHG was carried out using "peptidomics-modifications" methods. Nano-LC-MS/MS was used to analyze proteins and peptides in DH and DHG, and the number and sites of modification were determined as well. The amount of hydroxylation and deamidation that occurred in DHG was significantly greater than that in DH, suggesting that under thermal and high-pressure processing these modifications occurred more frequently on certain amino acids in collagen, and might be correlated with hydrophobicity. The occurrence and mechanism of hydroxylation and deamidation in DH processing procedures should be explored in further research. The present study provides important evidence of the chemical constituents and the correlation of processing procedures with these modifications, and also suggests some investigative ideas for DHG processing optimization and improvement of quality standards.

Antibody drug conjugates (ADCs), as they combine the targetability of monoclonal antibody and cytotoxicity of small molecules, are a growing class of therapeutics for cancer. The key factor of ADCs development is the accurate selection of parameters including tumor target, monoclonal antibody, cytotoxic payload, and linkage strategy of antibody to payload. Here, we summarize the main elements in the structural design and the development of ADCs, as well as the regulatory consideration of product manufacturing and control, which would be helpful for the research and development of ADCs.

The protective effects of cyclosporin A (CsA), an inhibitor of mitochondrial permeability transition pore (MPTP), on vascular permeability in sepsis rats were investigated. Cecal ligation and puncture (CLP)-induced sepsis rats were used for in vivo studies, and the effects of CsA (1 and 5 mg·kg^-1) on vascular permeability of lung, kidney, and intestine, mitochondrial respiratory control ratio, and the survival of the sepsis rats were observed. Lipopolysaccharide (LPS) was used for stimulating vascular endothelial cells (VECs) in vitro, and the effects of CsA on leakage of microvascular, immunofluorescence of zonula occludes-1 (ZO-1), and transendothelial electrical resistance (TER) were observed. All the animal welfare and experimental procedures are in accordance with the regulations of the Animal Ethics Committee of the Army Medical University. Compared with sham-operated group, the vascular permeability of lung, kidney, and intestine in sepsis rats increased significantly (P < 0.05). Compared with conventional treatment group, CsA could significantly decrease the vascular permeability of lung, kidney, and intestine (P < 0.05 or P < 0.01), and prolong the survival period. The results of microcirculation also showed that CsA could significantly reduce the permeability of mesenteric venules in sepsis rats. At the cellular level, LPS stimulation significantly increased the permeability of vascular endothelial cells, including the decrease of transmembrane resistance and protein expression of ZO-1 (P < 0.05). CsA can significantly reduce the increase of permeability of vascular endothelial cells induced by LPS stimulation (P < 0.01). The function of mitochondria in the kidneys and intestines of sepsis rats was obviously impaired, and the respiratory control ratio of mitochondria was decreased. LPS significantly increased MPTP opening of VECs, while CsA significantly inhibited MPTP opening and improved mitochondrial function. CsA may protect mitochondrial function by inhibiting the opening of MPTP and play a protective role in the vascular permeability of sepsis rats. This study will provide an insight for the treatment of sepsis vascular leakage.

The chemical constituents of gorgonian Junceella fragilis Ridley, collected from Ximao Island, the South China Sea, were investigated. A new briarane-type diterpenoid, named fragilide Y (1), together with five known compounds (2-6), namely fragilide D (2), cholesterol (3), ergosterol peroxide (4), 2'-deoxythymidine (5) and cis-thyminenol (6), were isolated from the acetone extract of J. fragilis. The structure of the new compound 1 was elucidated by extensive spectroscopic analysis, while the known compounds were identified by comparison with the reported data. In bioassay, none of these compounds displayed obvious anti-inflammatory and cytotoxic effects.

To date, CRISPR/Cas systems represent the most widely used tool for genome editing; however, its application scope for gene therapy has been largely limited due to its limited efficiency in activating homologydirected repair for DNA and off-target effect. Base editing is a new CRISPR/Cas-based genome-editing strategy, which allows single nucleotide to be precisely corrected in a narrow window scope on the target DNA or RNA by taking advantage of different nucleobase deaminases. Base editors include cytosine base editors (CBEs) and adenine base editors (ABEs), which can induce the conversions from C·G to T·A and A·T to G·C, respectively. Base editors work independently of double-strand DNA breaks (DSBs) and DNA donor templates, and thus they are extensively adopted for a wide range of therapeutic applications for genetic diseases, largely owing to their high efficiency and great specificity. In this review, we summarize the development of base editors and their potentials as therapeutic drugs for treating genetic diseases, and future outlooks are also discussed.

This paper aimed to investigate the release efficiency of peptide at carbon terminal triggered by tetrazine bioorthogonal click-to-release reaction, and further explored the potential application of this reaction in functional modification and mild cleavage in solid-phase peptide synthesis. Thirteen peptide derivatives modified by trans-cyclooctene (TCO) were designed and synthesized, which were reacted with tetrazine to release the peptides. The results showed that the release rates of peptide were 90.0% to 97.7% in one hour. The strategy has good compatibility with the functional side-groups and the length of peptides, which expands the applications scope of tetrazine bioorthogonal click-to-release reaction. At the same time, a novel bifunctional trans-cyclooctene molecule was designed and synthesized. The active peptide GIRLRG was modified by fluorophore on the solid-phase resin, and released through tetrazine click-to-release reaction under mild condition, providing a new strategy for the solid-phase modification and release strategy of the peptide.

To target neovasculature and tumor cells, a novel cationic liposome with verteporfin (BPD) active-loaded in lumen (CLL) was designed and its basic in vitro and in vivo behaviors were evaluated in this study. Calcium acetate gradient loading method was applied to encapsulate BPD actively and cationic lipid (2, 3-dioleoy-loxy-propyl)-trimethylammonium (DOTAP) was added by post-insertion for the positive charge of CLL. Results of characterization showed that the diameter and zeta-potential of CLL were around 100 nm and 28 mV, respectively. Compared with passive loading liposomes, CLL significantly enhanced the stability of BPD loading. What's more, the loaded BPD in lumen could switch off the fluorescence and photosensitization during blood circulation by homo-fluorescence resonance energy transfer (homo-FRET) effect, leading to the diminished phototoxicity to normal tissues. In vitro cellular uptake and cytotoxicity assay exhibited that positive charge dramatically enhanced the uptake of CLL both in vascular endothelial cells and tumor cells leading to superior therapeutic efficacy. In vivo study further showed that CLL reduced the clearance rate and increased tumor accumulation compared with passive loading group. Quantitative results of exvivo organ indicated that negligible CLL distributed in normal organs contributing to low phototoxicity. Animal experiments were conducted according to the Guidelines of the Experimental Animal Ethics Committee of Peking University Health Science Center and International Animal Experiments. In conclusion, we successfully designed a novel cationic targeting liposome that overcame the limitations of passive loading and significantly enhanced the efficacy of photodynamic therapy.

Natural products have been a major source of leading compounds in drug discovery. How to effectively screen active compounds from complex matrix remains an interesting topic. In this review, we comprehensively summarized advanced liquid chromatography based approaches in natural products screening, including pre-column, on-column and post-column screening methods. Their advantages, disadvantages and prospect are also discussed.

This research investigated the effect of parthenolide on the proliferation and migration of human breast cancer cells and explored the molecular mechanism of that effect. Surface plasmon resonance and fluorescence resonance energy transfer melting were used to detect the binding and stabilizing ability of PTL and G-quadruplex. MTT assays were used to determine the effect of PTL on the proliferation of MCF-7 breast cancer cells. A wound healing assay was performed to detect the migration of MCF-7. The results indicate that PTL shows good binding and stabilizing activities with c-myc G-quadruplex with a K_D=13.1 μmol·L^-1. PTL inhibited the proliferation of MCF-7 cells with an IC₅₀ of 21.3 μmol·L^-1 (24 h), 14.5 μmol·L^-1 (48 h) and 9.1 μmol·L^-1 (72 h). PTL inhibited MCF-7 breast cancer cell proliferation and migration and down-regulated the transcription and expression level of c-myc by targeting G-quadruplex.

To identify potential serum proteins that might serve as biomarkers for Alzheimer's disease (AD), we performed comparative proteomic profiling of sera from AD and healthy control subjects using label-free LC-MS/MS. Our study identified 387 proteins, 61 of which showed significant changes in the serum of AD patients compared to healthy controls. Gene ontology (GO) enrichment analysis showed that some GO terms related to the pathogenesis of AD were significantly enriched in differentially expressed proteins, including cholesterol and lipid metabolism, inflammation, coagulation and hemostasis processes, and immune responses. Therefore, based on the above results and the consistency of protein content changes in the 8 comparison groups, 18 proteins were selected as candidate biomarkers. Protein-protein interaction results suggest that these 18 proteins can directly or indirectly interact with APP. Therefore, changes in the levels or functions of these proteins may affect Aβ metabolism and participate in the occurrence of AD, and have the potential to become AD blood biomarkers.