Chemical synthesis and functional evaluation of glycopeptides and glycoproteins containing rare glycosyl amino acid linkages.

Covering: 1987 to 2023Naturally existing glycoproteins through post-translational protein glycosylation are highly heterogeneous, which not only impedes the structure-function studies, but also hinders the development of their potential medical usage. Chemical synthesis represents one of the most powerful tools to provide the structurally well-defined glycoforms. Being the key step of glycoprotein synthesis, glycosylation usually takes place at serine, threonine, and asparagine residues, leading to the predominant formation of the O- and N-glycans, respectively. However, other amino acid residues containing oxygen, nitrogen, sulfur, and nucleophilic carbon atoms have also been found to be glycosylated. These diverse glycoprotein linkages, occurring from microorganisms to plants and animals, play also pivotal biological roles, such as in cell-cell recognition and communication. The availability of these homogenous rare glycopeptides and glycoproteins can help decipher the glyco-code for developing therapeutic agents. This review highlights the chemical approaches for assembly of the functional glycopeptides and glycoproteins bearing these "rare" carbohydrate-amino acid linkages between saccharide and canonical amino acid residues and their derivatives.

Progress in Procalcitonin Detection Based on Immunoassay.

Procalcitonin (PCT) serves as a crucial biomarker utilized in diverse clinical contexts, including sepsis diagnosis and emergency departments. Its applications extend to identifying pathogens, assessing infection severity, guiding drug administration, and implementing theranostic strategies. However, current clinical deployed methods cannot meet the needs for accurate or real-time quantitative monitoring of PCT. This review aims to introduce these emerging PCT immunoassay technologies, focusing on analyzing their advantages in improving detection performances, such as easy operation and high precision. The fundamental principles and characteristics of state-of-the-art methods are first introduced, including chemiluminescence, immunofluorescence, latex-enhanced turbidity, enzyme-linked immunosorbent, colloidal gold immunochromatography, and radioimmunoassay. Then, improved methods using new materials and new technologies are briefly described, for instance, the combination with responsive nanomaterials, Raman spectroscopy, and digital microfluidics. Finally, the detection performance parameters of these methods and the clinical importance of PCT detection are also discussed.

Procalcitonin Detection Using Immunomagnetic Beads-Mediated Surface-Enhanced Raman Spectroscopy.

The early detection of procalcitonin (PCT) is crucial for diagnosing bacterial infections due to its high sensitivity and specificity. While colloidal gold colorimetric and immune-chemiluminescence methods are commonly employed in clinical detection, the former lacks sensitivity, and the latter faces challenges with a brief luminescence process and an elevated background. Here, we introduce a novel approach for the quantitative analysis of PCT using surface-enhanced Raman spectroscopy (SERS), leveraging the enhanced properties of metal nanoparticles. Simultaneously, we employed a magnetic nanoparticle coating and surface biofunctionalization modification to immobilize PCT-trapping antibodies, creating the required immune substrates. The resulting magnetic nanoparticles and antibody complexes, acting as carriers and recognition units, exhibited superparamagnetism and the specific recognition of biomarkers. Then, this complex efficiently underwent magnetic separation with an applied magnetic field, streamlining the cumbersome steps of traditional ELISA and significantly reducing the detection time. In conclusion, the exploration of immunomagnetic bead detection technology based on surface-enhanced Raman spectroscopy holds crucial practical significance for the sensitive detection of PCT.

Calcium Carbonate-Based Nanoplatforms for Cancer Therapeutics: Current State of Art and Future Breakthroughs.

With the rapid development of nanotechnology, nanomaterials have shown immense potential for antitumor applications. Nanosized calcium carbonate (CaCO3) materials exhibit excellent biocompatibility and degradability, and have been utilized to develop platform technologies for cancer therapy. These materials can be engineered to carry anticancer drugs and functional groups that specifically target cancer cells and tissues, thereby enhancing therapeutic efficacy. Additionally, their physicochemical properties can be tailored to enable stimuli-responsive therapy and precision drug delivery. This Review consolidates recent literatures focusing on the synthesis, physicochemical properties, and multimodal antitumor therapies of CaCO3-based nanoplatforms (CBN). We also explore the current challenges and potential breakthroughs in the development of CBN for antitumor applications, providing a valuable reference for researchers in the field.

Microfluidic printed 3D bioactive scaffolds for postoperative treatment of gastric cancer.

Tumor recurrence and tissue regeneration are two major challenges in the postoperative treatment of cancer. Current research hotspots are focusing on developing novel scaffold materials that can simultaneously suppress tumor recurrence and promote tissue repair. Here, we propose a microfluidic 3D-printed methacrylate fish gelatin (F-GelMA@BBR) scaffold loaded with berberine (BBR) for the postoperative treatment of gastric cancer. The F-GelMA@BBR scaffold displayed a significant killing effect on gastric cancer MKN-45 cells in vitro and demonstrated excellent anti-recurrence efficiency in gastric cancer postoperative models. In vitro experiments have shown that F-GelMA@BBR exhibits significant cytotoxicity on gastric cancer cells while maintaining the cell viability of normal cells. The results of in vivo experiments show that F-GelMA@BBR can significantly suppress the tumor volume to 49.7 % of the control group. In addition, the scaffold has an ordered porous structure and good biocompatibility, which could support the attachment and proliferation of normal cells to promote tissue repair at the tumor resection site. These features indicated that such scaffold material is a promising candidate for postoperative tumor treatment in the practical application.

Bio-Inspired Fractal Robust Hydrogel Catheter for Intra-Abdominal Sepsis Management.

To deal with intra-abdominal sepsis, one of the major global causes of death in hospitalized patients, efficient abscess drainage is crucial. Despite decades of advances, traditional catheters have demonstrated poor drainage and absorption properties due to their simple tubular structures and their dense nonporous surface. Herein, inspired by porous sponges and fractal roots, a multifaceted hydrogel catheter with effective drainage, absorptive, and robust properties, is presented. Its unique fractal structures provide extensive internal branching and a high specific surface area for effective drainage, while the hierarchical porous structures provide a wide range of absorption capabilities. Additionally, its distinctive multi-interpenetration network maintains robust and appropriate mechanical properties, even after absorption multiple times of liquid and mechanical disturbance, allowing for intact removal from the abdominal cavity without harm to the animal in vivo. Besides, the loaded antimicrobial peptides are capable of being released in situ to inhibit the potential for infections. In vivo experiments have demonstrated that this hydrogel catheter efficiently removes lethal abscesses and improves survival. It is believed that this innovative and practical catheter will create a future precedent for hydrogel drainage devices for more effective management of intra-abdominal sepsis.

Biomimetic Alveoli System with Vivid Mechanical Response and Cell-Cell Interface.

Alveolar microenvironmental models are important for studying the basic biology of the alveolus, therapeutic trials, and drug testing. However, a few systems can fully reproduce the in vivo alveolar microenvironment including dynamic stretching and the cell-cell interface. Here, a novel biomimetic alveolus-on-a-chip microsystem is presented suitable for visualizing physiological breathing for simulating the 3D architecture and function of human pulmonary alveoli. This biomimetic microsystem contains an inverse opal structured polyurethane membrane that achieves real-time observation of mechanical stretching. In this microsystem, the alveolar-capillary barrier is created by alveolar type 2 (ATII) cells cocultured with vascular endothelial cells (ECs) on this membrane. Based on this microsystem, the phenomena of flattening and the tendency of differentiation in ATII cells are observed. The synergistic effects of mechanical stretching and ECs on the proliferation of ATII cells are also observed during the repair process following lung injury. These features indicate the potential of this novel biomimetic microsystem for exploring the mechanisms of lung diseases, which can provide future guidance concerning drug targets for clinical therapies.

Photothermal Responsive Digital Polymerase Chain Reaction Resolving Exosomal microRNAs Expression in Liver Cancer.

Exosomal microRNAs have been studied as a good source of noninvasive biomarkers due to their functions in genetic exchange between cells and have been already well documented in many biological activities; however, inaccuracy remains a key challenge for liver cancer surveillance. Herein, a versatile duplex photothermal digital polymerase chain reaction (PCR) strategy combined with a lipid nanoparticle-based exosome capture approach is proposed to profile microRNAs expression through a 3-h easy-to-operate process. The microfluidically-generated molybdenum disulfide-nanocomposite-doped gelatin microcarriers display attractive properties as a 2-4 °C s-1 ramping-up rate triggered by near-infrared and reversible sol-gel transforming in step with PCR activation. To achieve PCR thermocycling, the corresponding irradiation coordinating with fan cooling are automatically performed via a homemade control module with programs. Thus, taking the multiplexing capability of dual-color labeling, 19-31 folds higher in exosomal microRNA-200b-3p and microRNA-21-5p, and tenfold lower in microRNA-22-3p expressions relative to the control microRNA-26a-5p are quantified in two liver cancer cells (Huh7 and HepG2) than in those from the healthy cells. It is believed that this exosomal microRNA genotyping method would be highly applicable for liver cancer diagnostics.

Oxygen-generating biocatalytic nanomaterials for tumor hypoxia relief in cancer radiotherapy.

Radiotherapy (RT), the most commonly used treatment method in clinics, shows unique advantages such as strong penetration, high energy intensity, and low systemic side effects. However, in vivo tumor hypoxia seriously hinders the therapeutic effect of RT. Hypoxia is a common characteristic of locally advanced solid tumor microenvironments, which leads to the proliferation, invasion and metastasis of tumor cells. In addition, oxygen consumption during RT will further aggravate tumor hypoxia, causing a variety of adverse side effects. In recent years, various biocatalytic nanomaterials (BCNs) have been explored to regulate and reverse tumor hypoxia microenvironments during RT. In this review, the most recent efforts toward developing oxygen-generating BCNs in relieving tumor hypoxia in RT are focused upon. The classification, engineering nanocatalytical activity of oxygen-generating BCNs and combined therapy based on these BCNs are systematically introduced and discussed. The challenges and prospects of these oxygen-generating BCNs in RT applications are also summarized.

Recent progress in the treatment of intractable sialolithiasis / 北京大学学报(医学版)

Sialolithiasis occurs in approximately 0.45% to 1.20% of the general population. The typical clinical symptom manifests as a painful swelling of the affected glands after a meal or upon salivary stimulation, which extremely affects the life quality of the patients. With the development of sialendoscopy and lithotripsy, most sialoliths can be successfully removed with preservation of the gland. However, sialoliths in the deep hilar-parenchymal submandibular ducts and impacted parotid stones located in the proximal ducts continue to pose great challenges. Our research center for salivary gland diseases (in Peking University School and Hospital of Stomatology) has used sialendoscopy for 17 years and treated >2 000 patients with salivary gland calculi. The success rate was approximately 92% for submandibular gland calculi and 95% for parotid calculi. A variety of minimally invasive surgical techniques have been applied and developed, which add substantial improvements in the treatment of refractory sialolithiasis. Further, the radiographic positioning criteria and treatment strategy are proposed for these intractable stones. Most of the hilar-parenchymal submandibular stones are successfully removed by a transoral approach, including transoral duct slitting and intraductal basket grasping, while a small portion of superficial stones can be removed by a mini-incision in submandibular area. Impacted stones located in the distal third of parotid gland ducts are removed via "peri-ostium incision", which is applied to avoid a cicatricial stenosis from a direct ostium incision. Impacted parotid stones located in the middle and proximal third of the Stensen's duct are removed via a direct mini-incision or a peri-auricular flap. A direct transcutaneous mini-incision is commonly performed under local anesthesia with an imperceptible scar, and is indicated for most of impacted stones located in the middle third, hilum and intraglandular ducts. By contrast, a peri-auricular flap is performed under general anesthesia with relatively larger operational injury of the gland parenchyma, and should be best reserved for deeper intraglandular stones. Laser lithotripsy has been applied in the treatment of sialolithiasis in the past decade, and holmium ∶YAG laser is reported to have the best therapeutic effects. During the past 3 years, our research group has performed laser lithotripsy for a few cases with intractable salivary stones. From our experiences, withdrawal of the endoscopic tip 0.5-1.0 cm away from the extremity of the laser fiber, consistent saline irrigation, and careful monitoring of gland swelling are of vital importance for avoidance of injuries of the ductal wall and the vulnerable endoscope lens during lithotripsy. Larger calculi require multiple treatment procedures. The risk of ductal stenosis can be alleviated by endoscopic dilation. In summary, appropriate use of various endoscopy-assisted lithotomy helps preserve the gland function in most of the patients with refractory sialolithiasis. Further studies are needed in the following aspects: Transcervical removal of intraglandular submandibular stones, intraductal laser lithotripsy of impacted parotid stones and deep submandibular stones, evaluation of long-term postoperative function of the affected gland, et al.

Aligned electrospun fiber film loaded with multi-enzyme mimetic iridium nanozymes for wound healing.

A film with elaborate microstructures that offers biomimetic properties and multi functionalities is highly desired in wound healing. Here, we develop an aligned hydrogel fiber film integrated with multi-active constituents to promote wound healing. Such fiber films are designed and constructed by photo-crosslinking the methacrylate gelatin (GelMA) doped with silver nanoparticles (Ag NPs) and iridium nanoparticles coated with polyvinylpyrrolidone (PVP-Ir NPs) in the precursor solution using electrospinning. The nature of GelMA hydrogel and the aligned arrangement of nanofibers endow the film with high-water content, self-degradability, improved bionic characteristics, oriented cell growth, and improved cell proliferation and migration. Moreover, the encapsulated nanozymes and Ag NPs offer the fiber film with superior reactive oxygen species (ROS) scavenging and antibacterial capability. The infected wound model shows that the multi-active hydrogel fiber film can reduce inflammation by killing bacteria and decomposing ROS, which accelerates the growth of new blood vessels and granulation tissue. Benefitting from these features, the versatile aligned GelMA fiber film demonstrates the clinically translational potential for wound healing.

Doxorubicin loaded hydrogel microparticles from microfluidics for local injection therapy of tumors.

Doxorubicin (DOX) is a powerful chemotherapy drug for cancer treatment, especially in patients with advanced cancer. However, clinical use of DOX remains challenging due to its widespread drug resistance and severe cardiotoxicity. Here, we developed a novel DOX-loaded natural hydrogel microparticle by using microfluidic electrospray technology. The designed carboxymethyl cellulose-based hydrogel microparticles were cross-linked by iron ions and showed a sustained drug release. The animal experiments revealed that DOX-loaded microparticles had good biocompatibility when locally injected into tumor-bearing mice, and could enhance the effect of chemotherapy and effectively inhibit tumor growth without obvious toxicity. These features indicated that the natural biomass-based hydrogel microparticles are highly promising for chemotherapy drugs delivery and provide a platform for local therapy.

Biodegradable MoO x @MB incorporated hydrogel as light-activated dressing for rapid and safe bacteria eradication and wound healing.

Wounds infected with drug-resistant bacteria are hard to treat, which remains a serious problem in clinical practice. An innovative strategy for treating wound infections is thus imperative. Herein, we describe the construction of a nanocomposite from biocompatible poly(vinyl alcohol) (PVA)/polyethylene glycol (PEG) hydrogel loaded biodegradable MoO x nanoparticles (NPs) and photosensitizer methylene blue (MB), denoted as MoO x @MB-hy. By incorporating MoO x @MB NPs, the nanocomposite hydrogel can act as a photoactivated wound dressing for near-infrared-II 1064 nm and 660 nm laser synergetic photothermal-photodynamic therapy (PTT-PDT). The key to PTT-induced heat becomes the most controllable release of MB from MoO x @MB-hy to produce more 1O2 under 660 nm irradiation. Importantly, MoO x @MB-hy can consume glutathione (GSH) and trap bacteria nearer to the distance limit of ROS damage to achieve a self-migration-enhanced accumulation of reactive oxygen species (ROS), thereby conquering the intrinsic shortcomings of short diffusion distance and lifetime of ROS. Consequently, MoO x @MB-hy has high antibacterial efficiencies of 99.28% and 99.16% against Ampr E. coli and B. subtilis within 15 min. Moreover, the light-activated strategy can rapidly promote healing in wounds infected by drug-resistant bacteria. This work paves a way to design a novel nanocomposite hydrogel dressing for safe and highly-efficient antibacterial therapy.

A Copper Peroxide Fenton Nanoagent-Hydrogel as an In Situ pH-Responsive Wound Dressing for Effectively Trapping and Eliminating Bacteria.

Bacterial infection has been a great threat to wounds due to the abuse of antibiotics and drug resistance. Elaborately constructing an efficient antibacterial strategy for accelerated healing of bacteria-infected wounds is of great importance. Herein, we develop a transferrin-conjugated copper peroxide nanoparticle-hydrogel (denoted as CP@Tf-hy) wound dressing with no toxicity to mammalian cells at a test dosage. When exposed to an initial acidic wound environment, the CP@Tf-hy simultaneously displays in situ self-supplied H2O2 and pH-responsive release of Fenton catalytic copper ions accompanied by highly toxic hydroxyl radical (•OH) generation against antibiotic-resistant bacteria. Meanwhile, the positively charged CP@Tf-hy can efficiently trap and restrain negatively charged bacteria to the range of •OH destruction to greatly overcome its intrinsic disadvantages of short life and diffusion distance. Importantly, the CP@Tf-hy consumes the bacterial overexpressed antioxidant glutathione while boosting Fenton catalytic copper(I) ions to generate more •OH. The synergistic effects of the enhanced Fenton reaction, responsive copper ion release, and bacterial trapping can achieve high bacterial elimination efficacy (7 log reduction). In vivo investigations demonstrate that the porous CP@Tf-hy significantly promotes hemostasis, cell proliferation, and migration of the wound, consequently accelerating bacteria-infected wound healing. The safe, low-cost, and all-in-one CP@Tf-hy holds great prospects as an antibacterial dressing for rapid resistant bacteria-infected purulent wound healing.

Primary Hyper-IgE-Related Salivary Gland Disease: A New Disease Entity.

OBJECTIVES: To clarify the clinicopathological characteristics of primary hyper-IgE-related salivary gland disease (PHIESD), which is a newly proposed entity. METHODS: Fifteen consecutive patients pathologically diagnosed with chronic sialadenitis were enrolled, and their clinicopathological features were comprehensively analyzed. INCLUSION CRITERIA: (1) multiple salivary gland enlargement; (2) elevated serum IgE and/or IgE-positive cell infiltration in salivary gland tissues; (3) histology-confirmed lymphoplasmacytic infiltration; (4) exclusion of other known diseases. RESULTS: The male-to-female ratio was 5:10. The median age was 21 (range, 3-63) years. The average number of affected glands was 3.7 ± 1.4. Submandibular, parotid, and sublingual glands were involved in 15, 8, and 2 patients, respectively. Comorbid diseases included allergic diseases in seven patients and autoimmune diseases in two. Elevated serum IgE (median 175 kU/L) was seen in all patients. Serum IgG4 was slightly elevated in three patients. Histologically, most patients had mild lesions, including mild lymphocyte infiltration (60%) and focal fibrosis (66.7%). Lymphoid follicular formation (53.3%), moderate to severe lymphocytic inflammation (40%) and severe fibrosis (33.3%) were also observed. Immunohistochemically, IgE-positive cells infiltrated mainly around the ducts, with scattered infiltration of IgG4-positive, mast, and interleukin-4 positive cells. During follow-up (median, 46 months) of ten patients without intervention and two with immunosuppressive therapy, no significant changes in gland size or serum IgE level were noted. CONCLUSIONS: PHIESD manifests as homogeneous enlargement of multiple salivary glands and elevated serum IgE. Histopathology further verifies the diagnosis. It might be associated with anaphylaxis or autoimmune dysfunction. Conservative treatment is suggested. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:2132-2138, 2022.

Synthesis and bioevaluation of diaryl urea derivatives as potential antitumor agents for the treatment of human colorectal cancer.

The development of inhibitors targeting the PI3K-Akt-mTOR signaling pathway has been greatly hindered by the on-target AEs, such as hyperglycemia and hepatotoxicities. In this study, a series of diaryl urea derivatives has been designed and synthesized based on clinical candidate gedatolisib (6aa), and most of the newly synthesized derivatives showed kinase inhibitory and antiproliferative activities within nanomolar and submicromolar level, respectively. The terminal l-prolineamide substituted derivative 6 ab showed 8.6-fold more potent PI3Kα inhibitory activity (0.7 nM) and 4.6-fold more potent antiproliferative effect against HCT116 cell lines (0.11 µM) compared with control 6aa. The potential antitumor mechanism and efficacy of 6 ab in HCT116 xenograft models have also been evaluated, and found 6 ab showed comparable in vivo antitumor activity with 6aa. The safety investigations revealed that compound 6 ab exhibited more safer profiles in the selectivity of liver cells (selectivity index: >6.6 vs 1.85) and blood glucose regulation than 6aa. In addition, the in vitro stability assays also indicated our developed compound 6 ab possessed good metabolic stabilities.

Liquid-Phase Manipulation Securing Enhanced Thermoelectric Performance of Ag2Se.

Developing n-type materials with high peak and/or average ZT (ZT is the figure of merit) is an urgent need for the lower ZT of the existing n-type BiTeSe materials compared with the p-type BiSbTe materials. Here, we demonstrate that liquid-phase sintering can lead to lowered thermal conductivity and an improved power factor in n-type Ag2Se, which originates from the greatly lowered electronic thermal conductivity attributed to the decreased mobility and improved Seebeck coefficients because of increased effective mass. Benefiting from this, the maximum ZT (ZTmax) of ∼1.21 and the average ZT (ZTave) of 1.06 are successfully achieved in polycrystalline Ag2Se. In this work, ZTave is the highest reported value, being 26% larger than that of Ag2Se reported. Our work shows that liquid-phase sintering to achieve improved thermoelectric (TE) performance opens a great opportunity for designing prospective thermoelectrics.

PGC-1α activates SIRT3 to modulate cell proliferation and glycolytic metabolism in breast cancer.

Breast cancer is the leading cause of death among women. PGC-1α plays an important role in the regulation of metabolic reprogramming in cancer cells. SIRT3 has significant implications for tumor growth. In this study, we explored the roles of PGC-1α and SIRT3 in cell proliferation and mitochondrial energy metabolism alterations in breast cancer cells. The expression patterns of PGC-1α and SIRT3 were examined using qRT-PCR and western blotting analysis. MCF-7 and MDA-MB-231 cells were infected with adenovirus to overexpress or knock down the expression of PGC-1α and SIRT3. Cell viability and apoptosis were analyzed by CCK-8 and flow cytometry, respectively. Hexokinase 2, pyruvate kinase activities, as well as NAD+/NADH ratio and ATP concentration, were assessed by commercial kits. Glucose consumption was measured using the glucose oxidase method and lactic acid concentration was detected by lactate dehydrogenase kit. Expression levels of PGC-1 and SIRT3 were much lower in breast cancer patients, compared with the normal controls. Overexpression of PGC-1α or SIRT3 both significantly promoted the apoptosis and inhibited the proliferation in MCF-7 and MDA-MB-231 cells. Additionally, PGC-1α or SIRT3 also induced the inhibition of glycolysis metabolism. Moreover, the expression of SIRT3 was positively regulated by PGC-1α. Silencing SIRT3 partly reversed the negative effects of PGC-1α on glycolytic metabolism. These findings demonstrated that PGC-1α/SIRT3 regulated cell proliferation and apoptosis of breast cancer through altering glycolysis, which may provide novel therapeutic strategies for breast cancer.