A scaffold vaccine to promote tumor antigen cross-presentation via sustained toll-like receptor-2 (TLR2) activation.

Cancer vaccination holds great promise for cancer treatment, but its effectiveness is hindered by suboptimal activation of CD8+ cytotoxic T lymphocytes, which are potent effectors to mediate anti-tumor immune responses. A possible solution is to switch antigen-presenting cells to present tumor antigens via the major histocompatibility complex class I (MHC-I) to CD8+ T cells - a process known as cross-presentation. To achieve this goal, we develop a three-dimensional (3D) scaffold vaccine to promote antigen cross-presentation by persisted toll-like receptor-2 (TLR2) activation after one injection. This vaccine comprises polysaccharide frameworks that "hook" TLR2 agonist (acGM) via tunable hydrophobic interactions and forms a 3D macroporous scaffold via click chemistry upon subcutaneous injection. Its retention-and-release of acGM enables sustained TLR2 activation in abundantly recruited dendritic cells in situ, inducing intracellular production of reactive oxygen species (ROS) in optimal kinetics that crucially promotes efficient antigen cross-presentation. The scaffold loaded with model antigen ovalbumin (OVA) or tumor specific antigen can generate potent immune responses against lung metastasis in B16-OVA-innoculated wild-type mice or spontaneous colorectal cancer in transgenic ApcMin/+ mice, respectively. Notably, it requires neither additional adjuvants nor external stimulation to function and can be adjusted to accommodate different antigens. The developed scaffold vaccine may represent a new, competent tool for next-generation personalized cancer vaccination.

Tumor-associated macrophages-educated reparative macrophages promote diabetic wound healing.

Nonhealing diabetic wounds, with persistent inflammation and damaged vasculature, have failed conventional treatments and require comprehensive interference. Here, inspired by tumor-associated macrophages (TAMs) that produce abundant immunosuppressive and proliferative factors in tumor development, we generate macrophages to recapitulate TAMs' reparative functions, by culturing normal macrophages with TAMs' conditional medium (TAMs-CM). These TAMs-educated macrophages (TAMEMs) outperform major macrophage phenotypes (M0, M1, or M2) in suppressing inflammation, stimulating angiogenesis, and activating fibroblasts in vitro. When delivered to skin wounds in diabetic mice, TAMEMs efficiently promote healing. Based on TAMs-CM's composition, we further reconstitute a nine-factor cocktail to train human primary monocytes into TAMEMsC-h , which fully resemble TAMEMs' functions without using tumor components, thereby having increased safety and enabling the preparation of autologous cells. Our study demonstrates that recapitulating TAMs' unique reparative activities in nontumor cells can lead to an effective cell therapeutic approach with high translational potential for regenerative medicine.

Construction of the prognostic signature of alternative splicing revealed the prognostic predictor and immune microenvironment in head and neck squamous cell carcinoma.

Background: Head and neck squamous cell carcinoma (HNSC) is a prevalent and heterogeneous malignancy with poor prognosis and high mortality rates. There is significant evidence of alternative splicing (AS) contributing to tumor development, suggesting its potential in predicting prognosis and therapeutic efficacy. This study aims to establish an AS-based prognostic signature in HNSC patients. Methods: The expression profiles and clinical information of 486 HNSC patients were downloaded from the TCGA database, and the AS data were downloaded from the TCGA SpliceSeq database. The survival-associated AS events were identified by conducting a Cox regression analysis and utilized to develop a prognostic signature by fitting into a LASSO-regularized Cox regression model. Survival analysis, univariate and multivariate Cox regression analysis, and receiver operating characteristic (ROC) curve analysis were performed to evaluate the signature and an independent cohort was used for validation. The immune cell function and infiltration were analyzed by CIBERSORT and the ssGSEA algorithm. Results: Univariate Cox regression analysis identified 2726 survival-associated AS events from 1714 genes. The correlation network reported DDX39B, PRPF39, and ARGLU1 as key splicing factors (SF) regulating these AS events. Eight survival-associated AS events were selected and validated by LASSO regression to develop a prognostic signature. It was confirmed that this signature could predict HNSC outcomes independent of other variables via multivariate Cox regression analysis. The risk score AUC was more than 0.75 for 3 years, highlighting the signature's prediction capability. Immune infiltration analysis reported different immune cell distributions between the two risk groups. The immune cell content was higher in the high-risk group than in the low-risk group. The correlation analysis revealed a significant correlation between risk score, immune cell subsets, and immune checkpoint expression. Conclusion: The prognostic signature developed from survival-associated AS events could predict the prognosis of HNSC patients and their clinical response to immunotherapy. However, this signature requires further research and validation in larger cohort studies.

A "Nonsolvent Quenching" Strategy for 3D Printing of Polysaccharide Scaffolds with Immunoregulatory Accuracy.

3D printing enables the customized design of implant structures for accurately regulating host responses. However, polysaccharides, as a major biomaterial category with versatile immune activities, are typically "non-printable" due to the collapse of their filaments extruded during printing. This challenge renders their potential as immunomodulatory scaffolds underexploited. Here, inspired by the quench hardening in metal processing, a nonsolvent quenching (NSQ) strategy is innovatively designed for the 3D printing of polysaccharides. Through rapid solvent exchanging, NSQ instantly induces surface hardening to strengthen the polysaccharide filaments upon extrusion, requiring neither chemical modification nor physical blending that alters the material properties. Tested with five polysaccharides with varying physicochemical properties, NSQ prints predesigned structures at organ-relevant scales and a long shelf-life over 3 months. Glucomannan scaffolds, fabricated via NSQ with different grid spacings (1.5 and 2.5 cm), induce distinct host responses upon murine subcutaneous implantation-from specific carbohydrate receptor activation to differential immunocytes accumulation and tissue matrix remodeling-as mechanistically validated in wild-type and Tlr2-/- knockout mice. Overall, NSQ as a facile and generic strategy is demonstrated to fabricate polysaccharide scaffolds with improved shape fidelity, thereby potentially unmasking their accurate immunomodulatory activities for future biomaterials design.

Reprograming the immune niche for skin tissue regeneration - From cellular mechanisms to biomaterials applications.

Despite the rapid development of therapeutic approaches for skin repair, chronic wounds such as diabetic foot ulcers remain an unaddressed problem that affects millions of people worldwide. Increasing evidence has revealed the crucial and diverse roles of the immune cells in the development and repair of the skin tissue, prompting new research to focus on further understanding and modulating the local immune niche for comprehensive, 'perfect' regeneration. In this review, we first introduce how different immunocytes and certain stromal cells involved in innate and adaptive immunity coordinate to maintain the immune niche and tissue homeostasis, with emphasis on their specific roles in normal and pathological wound healing. We then discuss novel engineering approaches - particularly biomaterials systems and cellular therapies - to target different players of the immune niche, with three major aims to i) overcome 'under-healing', ii) avoid 'over-healing', and iii) promote functional restoration, including appendage development. Finally, we highlight how these strategies strive to manage chronic wounds and achieve full structural and functional skin recovery by creating desirable 'soil' through modulating the immune microenvironment.

Destructing biofilms by cationic dextran through phase transition.

Eliminating biofilms from infected tissue presents one of the most challenging issues in clinical treatment of chronic wounds. In biofilms, the extracellular polymeric substances (EPS) form gel structures by electrostatic forces between macromolecules. We hypothesized that cationic polymers could induce the gel-to-sol phase transition of the network, leading to biofilms disruptions. We first validated this assumption by using polyethyleneimine (PEI) as a model molecule, and further synthesized two cationic dextrans with high biodegradability for in vitro and in vivo evaluation. All the cationic polymers could destruct Pseudomonas aeruginosa (P. aeruginosa) biofilms. Treating biofilm with cationic dextrans significantly enhanced the bacterial antibiotic sensitivity. When tested in a biofilm-presenting mouse wound healing model, the cationic dextrans efficiently controlled infection, and accelerated the healing process. Our findings suggest that devising cationic polymers to trigger phase transition of biofilm is an effective, straightforward, and perhaps generic strategy for anti-bacterial therapies.

A "Bridge-Building" Glycan Scaffold Mimicking Microbial Invasion for In Situ Endothelialization.

The globally high prevalence of peripheral artery diseases poses a pressing need for biomaterials grafts to rebuild vasculature. When implanted, they should promote endothelial cells (ECs) adhesion both profoundly and selectively-but the latter expectation remains unfulfilled. Here, this work is inspired by fungi that invade blood vessels via the "bridge" of galectins that, secreted by ECs, can simultaneously bind carbohydrates on fungal surface and integrin receptors on ECs. A glucomannan decanoate (GMDE) substrate mimicking fungal carbohydrates that highly and preferentially supports ECs adhesion while rejecting several other cell types is designed. Electrospun GMDE scaffolds efficiently sequester endogenous galectin-1-which bridges ECs to the scaffolds as it functions in fungal invasions-and promote blood perfusion in a murine limb ischemic model. Meanwhile, the application of GMDE requires no exogenous pro-angiogenic agents and causes no organ toxicity or adverse inflammation in mice, highlighting its high safety of potential translation. This glycan material, uniquely mimicking a microbial action and harnessing a secreted protein as a "bridge," represents an effective, safe, and different strategy for ischemic vascular therapy.

Polysaccharides from tubers of Bletilla striata: Physicochemical characterization, formulation of buccoadhesive wafers and preliminary study on treating oral ulcer.

The purpose of this research is to arouse people's cognition of the dual role of Bletilla striata polysaccharide (BSP)-a kind of biocompatible, biodegradable natural biological materials with myriad pharmacological activities. BSP was extracted and characterized firstly. The results indicated that BSP was composed of mannose and glucose. The backbone of BSP mainly consisted of (1 → 4)-linked ß-D-mannopyranose. Afterwards, A 32 factorial design was employed for optimization of lyophilized wafers for the treatment of traumatic oral ulcer with concentrations of BSP and glycerin as independent variables. Tensile strength, mucoadhesive strength, and swelling index were measured as response variables. It was determined that the wafer prepared from a solution containing 4% (w/v) BSP and 7% (w/v) glycerin was the optimal formulation. The wafers exhibited sufficient mechanical strength and suitable surface pH. Morphology of the wafers was observed. DSC/TGA thermograms showed the presence of three peaks weight loss events and decomposition patterns. Moreover, in vivo examinations indicated that the BSP wafer significantly promoted ulcer healing at 7 days, while no statistically significant difference was observed on day 12. In conclusion, this study suggests that BSP is an ideal biomaterial for mucosal adhesion agents, playing a nontrivial role in promoting oral ulcer healing.

Novel Bletilla striata polysaccharide microneedles: Fabrication, characterization, and in vitro transcutaneous drug delivery.

Dissolving microneedles (MNs) have been widely studied for their applications in effective transdermal drug delivery due to their ability to dissolve within the skin. This study details the first reported successful preparation of novel dissolving MNs using Bletilla striata polysaccharide (BSP), a natural glucomannan material, and investigates the potential for using such MNs as a transdermal drug delivery vector. The prepared dissolving Bletilla striata polysaccharide microneedles (BMNs) had excellent moldability and were easily detached from the mold. Texture analysis and histological examination confirmed BMNs were strong enough to insert into the skin. The skin appeared slight irritation after removal of BMNs, but recovered within 24 h. Confocal laser scanning microscopy (CLSM) studies indicated that rhodamine B (RB) loaded in BMNs (as a model drug) could be gradually released, along with the dissolution of BSP in vivo, and then diffused from the insertion site to the periphery. Furthermore, we found that the RB-loaded BMNs could provide sustained drug release via the in vitro Franz cell experiment. These findings demonstrate that novel dissolving BMNs can be easily-manufactured, loaded with drug, and inserted into the skin for drug delivery.

Bletilla striata Micron Particles Function as a Hemostatic Agent by Promoting Rapid Blood Aggregation.

The human body cannot control blood loss without treatment. Available hemostatic agents are ineffective at treating cases of severe bleeding and are expensive or raise safety concerns. Bletilla striata serve as an inexpensive, natural, and promising alternative. However, no detailed studies on its hemostatic approach have been performed. The aim of this study was to examine the hemostatic effects of B. striata Micron Particles (BSMPs) and their hemostatic mechanisms. We prepared and characterized BSMPs of different size ranges and investigated their use as hemostatic agent. BSMPs of different size ranges were characterized by scanning electron microscope. In vitro coagulation studies revealed BSMP-blood aggregate formation via stereoscope and texture analyzers. In vivo studies based on rat injury model illustrated the BSMP capabilities under conditions of hemostasis. Compared to other BSMPs of different size ranges, BSMPs of 350-250 µm are most efficient in hemostasis. As powder sizes decrease, the degree of aggregation between particles and hemostatic BSMP effects declines. The BSMP in contact with a bleeding surface locally forms a visible particle/blood aggregate as a physical barrier that facilitates hemostasis. Considering the facile preparation, low cost, and long shelf life of B. striata, BSMPs offer great potential as mechanisms of trauma treatment.