Natural Deep Eutectic Solvent-Assisted Extraction, Structural Characterization, and Immunomodulatory Activity of Polysaccharides from Paecilomyces hepiali.

Polysaccharides, which can be affected by different preparations, play a crucial role in the biological function of Paecilomyces hepiali (PHPS) as a health food. To explore high-valued polysaccharides and reduce the negative influence of human involvement, a green tailorable deep eutectic solvent (DES) was applied to optimize the extraction of polysaccharides (PHPS-D), followed by the evaluation of the structural properties and immunomodulation by comparison with the hot-water method (PHPS-W). The results indicated that the best system for PHPS-D was a type of carboxylic acid-based DES consisting of choline chloride and succinic acid in the molar ratio of 1:3, with a 30% water content. The optimal condition was as follows: liquid-solid ratio of 50 mL/g, extraction temperature of 85 °C, and extraction time of 1.7 h. The actual PHPS-D yield was 12.78 ± 0.17%, which was obviously higher than that of PHPS-W. The structural characteristics suggested that PHPS-D contained more uronic acid (22.34 ± 1.38%) and glucose (40.3 ± 0.5%), with a higher molecular weight (3.26 × 105 g/mol) and longer radius of gyration (78.2 ± 3.6 nm), as well as extended chain conformation, compared with PHPS-W, and these results were confirmed by AFM and SEM. Immunomodulatory assays suggested that PHPS-D showed better performance than PHPS-W regarding pinocytic activity and the secretion of NO and pro-inflammatory cytokines (IL-6, TNF-α and IL-1ß) by activating the corresponding mRNA expression in RAW264.7 cells. This study showed that carboxylic acid-based DES could be a promising tailorable green system for acidic polysaccharide preparation and the valorization of P. hepiali in functional foods.

[Effects of nitrogen level on growth of Tetrastigma hemsleyanum and phytochemical content and antioxidant activity in stems and leaves].

As a rare endangered medical plant that newly cultivated,little experimental information is available for growth and metabolites of Tetrastigma hemsleyanum in response to nitrogen( N). The effects of different levels of N on growth of T. hemsleyanum and the content of phytochemicals( polysaccharide,total flavonoids and phenolics) and antioxidant activity( ABTS and FRAP) in stems and leaves were investigated in this study. A certain amount of N had positive effects on most of biological traits,and excessive dose of N went against growth of T. hemsleyanum. With N levels decreased,the polysaccharide content in stems and leaves had no significant change,while the total flavonoid and phenolic content,and antioxidant activities increased steadily. Antioxidant activities and total flavonoid and phenolic content had significant positive correlation. Excessive N fertilizer should be avoided by cultivation.

Optimization Extraction, Preliminary Characterization and Antioxidant Activities of Polysaccharides from Semen Juglandis.

The optimization extraction process, preliminary characterization and antioxidant activities of polysaccharides from Semen Juglandis (SJP) were studied in this paper. Based on the Box-Behnken experimental design and response surface methodology, the optimal extraction conditions for the SJP extraction were obtained as follows: temperature 88 °C, extraction time 125 min and ratio of liquid to solid 31 mL/g. Under these conditions, experimental extraction yield of SJP was (5.73 ± 0.014)% (n = 5), similar to the predicted value of 5.78%. Furtherly, the purified SJP obtained from SJP extract by DEAE-52 and Sephacryl S-100 chromatography was analyzed to be rhamnose, galacturonic acid, galactose, arabinose and fucose in the molar ratio of 1:6.34:1.38:3.21:1.56. And the weight-average molecular weight and radius of gyration of the purified SJP in 0.1 M NaCl were determined to be 2.76 × 104 g/mol and 122 nm by SEC-MALLS, respectively. More importantly, it exhibited appreciable antioxidant activities compared to the standard Vc, such as DPPH radical scavenging activity (IC50 0.21 mg/mL), strong reducing power, ABTS radical scavenging activity (IC50 0.29 mg/mL), and hydroxyl radical scavenging activity (IC50 0.38 mg/mL). These results indicate that SJP may be useful for developing functional health products or natural antioxidant.

Third-order optical nonlinearity at 800 and 1300 nm in bismuthate glasses doped with silver nanoparticles.

Large and ultrafast third-order optical nonlinearities in Ag-doped bismuthate glasses which are prepared by incorporating Ag ions into bismuthate glasses to form Ag nanoparticles through a consecutive melting-quenching-annealing technique are reported. Due to the high refractive index of bismuthate glass, surface plasmon resonance (SPR) of Ag nanoparticles is extendable to 1400 nm, resulting in a higher nonlinear refractive index than bismuthate glass. Femtosecond Z-scans show that the nonlinear refractive index, as high as 9.4 × 10(-17) and 5.6 × 10(-18) m(2) W(-1) at 800 and 1300 nm, respectively, can be achieved by selecting an optimized concentration of Ag nano-sized particles. And two-photon absorption at 800 nm is suppressed due to a blue shift in the band-gap of Ag-doped bismuthate glasses, as compared to pristine bismuthate glasses. Optical Kerr shutter technique reveals that these nonlinearities have a relaxation time of < 1 ps.

Efficacy comparison between intramedullary nail fixation and plate fixation in distal tibia fractures: a meta-analysis of randomized controlled trials.

BACKGROUND: Intramedullary nail (IMN) and plate fixation are the most commonly used surgical modalities for distal tibia fractures. However, the superiority of their efficacy regarding functional outcomes and complications remains controversial. Here, we performed a systematic review and meta-analysis to compare the efficacy of these two modalities. METHODS: Randomized controlled trials (RCTs) comparing the efficacy of IMN and plate fixation in distal tibia fractures were searched in PubMed, Web of Science, EMBASE, ClinicalTrials.gov, and Cochrane Library up to January 31, 2024. Weighted mean difference (WMD) and odds ratio (OR) with corresponding 95% confidence interval (CI) were estimated using a random-effect model for continuous and categorical outcomes, respectively. RESULTS: A total of 20 RCTs comprising 1528 patients were included. Compared with plate fixation, IMN significantly shortened surgery time (WMD=-10.73 min, 95%CI: -15.93 to -5.52), union time (WMD=-1.56 weeks, 95%CI: -2.82 to -0.30), and partial (WMD=-1.71 weeks, 95%CI: -1.91 to -0.43) and full (WMD=-2.61 weeks, 95%CI: -3.53 to -1.70) weight-bearing time. IMN was associated with markedly reduced risk of wound infection (OR = 0.44, 95%CI: 0.31-0.63) and secondary procedures (OR = 0.72, 95%CI: 0.55-0.95), but increased the risk of malunion (OR = 1.53, 95%CI: 1.02-2.30) and anterior knee pain (OR = 3.94, 95%CI: 1.68-9.28). The rates of nonunion, delayed union, and functional assessment scores did not significantly differ between the two groups. The percentages of patients obtaining an excellent functional outcome or an excellent and good functional outcome post-operation were comparable. CONCLUSIONS: Both IMN and plate fixation are effective modalities for the surgical treatment of distal tibia fractures. IMN seems to be preferred since it confers more advantages, but the elevated rates of malunion and knee pain require attention. The decision on fixation modality should be tailored to the specific fracture, considering these pros and cons.

Association of various fruiting body macromorphological traits with spore yield in Ganoderma Lingzhi (higher Basidiomycetes), a new medicinal mushroom from China.

To study the correlations and relationship between spore yield and various macromorphological traits of Ganoderma lingzhi, a field experiment was conducted in a randomized block design with 3 replications. Ten macromorphological traits, including pileus diameter, pileus crust thickness, context thickness, tube thickness, pileus thickness, stipe length, stipe diameter, stipe weight, pileus weight, and spore yield, were recorded for all of the tested strains. There was significant variation among the strains for all of the traits studied. The results indicated that the highest variation was observed in spore yield and pileus weight. Correlation studies revealed that among 9 macromorphological traits, only the pileus weight of the fruiting body was significantly positively correlated with spore yield (r2 = 0.674*). Pileus diameter showed significant positive association with pileus weight of fruiting body (r2 = 0.838*). Stepwise multiple regression analysis showed that pileus weight and spore yield had a linear relationship (spore yield = -21.95 + 1.51 * pileus weight). The coefficient of determination of stepwise regression analysis (r2 = 0.4543) revealed 45.43% variation in the spore yield because of its relationship with pileus weight. Regression coefficient (b = 1.51) showed that a unit (1 g) increase in the pileus weight of the fruiting body resulted in a proportional increase of 1.51 g in spore yield. The derived information would be very useful when selecting potentially breeding strains for future G. lingzhi improvement programs.

Molecular Characterization and Bioactivities of a Novel Polysaccharide from Phyllostachys pracecox Bamboo Shoot Residues.

Dietary carbohydrates are unexploited in the by-products of economically valuable Phyllostachys pracecox bamboo shoots. A residue-derived polysaccharide (PBSR1) was aqueously extracted from the processing waste of this bamboo shoot species. Its primary structure and advanced conformation were elucidated by a combined analysis of spectroscopy, chromatography, 2D nuclear magnetic resonance, laser light scattering and atomic microscopy. The results indicated PBSR1 was a triple-helix galactan consisting of →6)-ß-D-Galp and →3)-ß-D-Galp in linear with an 863 KD molecular weight (Mw). The relationship between the radius of gyration (Rg) and intrinsic viscosity ([η]) on Mw were established as Rg = 1.95 × 10-2Mw0.52±0.03 (nm) and [η] = 9.04 × 10-1Mw0.56±0.02 (mL/g) for PBSR1 in saline solution at 25 °C, which indicated it adopted a triple-helix chain shape with a height of 1.60 ± 0.12 nm supported by a red shift of λmax in Congo red analysis. The thermodynamic test (TG) displayed that it had excellent thermal stability for the food industry. Further, those unique structure features furnish PBSR1 on antioxidation with EC50 of 0.65 mg/mL on DPPH· and an ORAC value of 329.46 ± 12.1 µmol TE/g. It also possessed pronounced immunostimulation by up-regulating pro-inflammatory signals including NO, IL-6, TNF-α and IL-1ß in murine cells. Our studies provided substantial data for the high-valued application of residues and a better understanding of the structure-function relationship of polysaccharide.

Fermentation-mediated variations in structure and biological activity of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg.

Variations in the structure and activities of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg fermented by Sanghuangporus sanghuang fungi were investigated. Compare with the unfermented polysaccharide (THDP2), the major monosaccharide composition and molecular weight of polysaccharide after fermentation (F-THDP2) altered dramatically, which caused galactose-induced conversion from glucose and one-third of molecular weight. F-THDP2 had a molecular weight of 1.23 × 104 Da. Moreover, the glycosidic linkage of F-THDP2 varied significantly, a 1, 2-linked α-d-Galp and 1, 2-linked α-d-Manp backbone was established in F-THDP2, which differed from that of 1, 4-linked α-d-Glcp and 1, 4-linked ß-d-Galp in THDP2. In addition, F-THDP2 showed a more flexible chain conformation than that of THDP2 in aqueous solution. Strikingly, F-THDP2 exhibited superior inhibitory effects on HeLa cells via Fas/FasL-mediated Caspase-3 signaling pathways than that of the original polysaccharide. These variations in both structure and biological activities indicated that fermentation-mediated modification by Sanghuangporus sanghuang might a promising novel method for the effective conversion of starch and other polysaccharides from Tetrastigma hemsleyanum Diels et Gilg into highly bioactive biomacromolecules, which could be developed as a potential technology for use in the food industry.

Optimization of fermentation process for the production of intracellular polysaccharide from Paecilomyces cicadae and the immuno-stimulating activity of intracellular polysaccharide.

Optimization of fermentation process for the production of intracellular polysaccharide (IPS) from the fungus Paecilomyces cicadae and the immuno-stimulating activity of IPS were carried out. The quantitative effects of initial pH, fermentation temperature and time on the yield of IPS content produced by P. cicadae in submerged fermentation were investigated separately using response surface methodology (RSM). The three factors chosen for the present investigation were based on the results of a previous Plackett-Burman (PB) design. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed by appropriate statistical methods. RSM analysis showed good correspondence between experimental and predicted values. It was found that three parameters represented significant effect. Probability value (p < 0.0001) demonstrated a very high significance for the regression model. By solving the regression equation and analyzing the response surface contour plots, the optimal process parameters were determined, i.e. fermentation temperature 24.53 °C, initial pH 7.46 and fermentation time 73.9 h. The maximum predicted yield of IPS was 356.02 µg/ml under the optimal conditions. Meanwhile, IPS from P. cicadae was found to have direct immuno-stimulating activity in vitro on murine macrophage RAW264.7 proliferative response and to stimulate nitric oxide generation in a dose-dependent manner.

Efficient purification of flavonoids from bamboo shoot residues of Phyllostachys edulis by macroporous resin and their hypoglycemic activity.

The adsorption/desorption process of flavonoids obtained from bamboo shoots residues of Phyllostachys edulis (RPEFs) was established by resin screening, adsorption isotherms, adsorption kinetics and dynamic tests. Results indicated the Langmuir equation fairly fitted the isotherms data and the pseudo-second-order model accurately described its kinetic adsorption on HPD-500 resin. The optimal process was as follows: 2 mg/mL of solution, 2.8 BV feed volume under 2 BV/h flow rate for adsorption; 5 BV volume of 70 % ethanol with a flow rate of 2 BV/h for desorption. After enrichment, the flavonoids in RPEFs increased from 1.39 % to 37.34 %. The analysis of UPLC-TOF-MS/MS uncovered that the purified RPEFs were composed of four major flavonoids. It had potent hypoglycemic activity via PI3K/AKT pathway by upregulating the protein expression of PI3K, AKT, IRS-1, and GLUT4 in a dose-dependent manner based on HepG2-IR cells. Those results provide possible utilization of Phyllostachys edulis by-products in food additives.

Conformation and anticancer activity of a novel mannogalactan from the fruiting bodies of Sanghuangporus sanghuang on HepG2 cells.

A novel water-soluble mannogalactan (SSPS1) with an average molecular weight of 2.04 × 104 Da was obtained from the fruiting bodies of the Sanghuangporus sanghuang. It revealed that SSPS1 was composed of d-galactose, d-mannose, l-fucose, 3-O-methylgalactose and d-glucose in a ratio of 6.2:3.9:3.1:2.1:1.0. The structural elucidation of SSPS1 consisted of 1, 6-linked α-D-Galp, 1, 6-linked α-D-Manp and 1, 6-linked 3-O-methyl-α-D-Galp backbone with branching at O-2 of 1, 6-α-D-mannosyl residues by α-L-Fucp and α-D-Glcp units. The conformational parameters suggested that a flexible chain conformation of SSPS1 in solution based on light scattering and atomic force microscopy imaging. Intriguingly, it presented potent anticancer activity on HepG2 cell with Rq and Ra values increased dramatically up to 73.93 nm and 53.92 nm compared with the control. The analysis of flow cytometry indicated SSPS1 could induce the apoptosis of HepG2 cells and arrest them via S phase. Western blot assay further uncovered that apoptosis process was triggered by SSPS1 via a mitochondria-mediated signaling pathway, which was evidenced by an increased ratio of Bax/Bcl-2, the release of cytochrome c and the strong activation of caspase-3 and 9. Taken together, these results suggested that SSPS1 might be applied in functional food as an anticancer agent.

Characterization, immunostimulatory and antitumor activities of a ß-galactoglucofurannan from cultivated Sanghuangporus vaninii under forest.

A biomacromolecule, named as ß-galactoglucofurannan (SVPS2), was isolated from the cultivated parts of Sanghuangporus vaninii under the forest. Its primary and advanced structure was analyzed by a series of techniques including GC-MS, methylation, NMR, MALS as well as AFM. The results indicated that SVPS2 was a kind of 1, 5-linked ß-Glucofurannan consisting of ß-glucose, ß-galactose and α-fucose with 23.4 KDa. It exhibited a single-stranded chain with an average height of 0.72 nm in saline solution. The immunostimulation test indicated SVPS2 could facilitate the initiation of the immune reaction and promote the secretion of cytokines in vitro. Moreover, SVPS2 could mediate the apoptosis of HT-29 cells by blocking them in S phase. Western blot assay revealed an upregulation of Bax, Cytochrome c and cleaved caspase-3 by SVPS2, accompanied by a downregulation of Bcl-2. These results collectively demonstrate that antitumor mechanism of SVPS2 may be associated with enhancing immune response and inducing apoptosis of tumor cells in vitro. Therefore, SVPS2 might be utilized as a promising therapeutic agent against colon cancer and functional food with immunomodulatory activity.

Common Variants of the OPG gene Are Associated with Osteoporosis Risk: A Meta-Analysis.

Background: The RANKL/RANK/OPG signaling pathway plays a critical role in osteoclastogenesis and bone remodeling. The associations between sequence variants of the osteoprotegerin (OPG) gene and osteoporosis risk have been widely investigated but remain inconclusive. Objective: We performed a meta-analysis to evaluate the associations between OPG gene variants and osteoporosis risk. Methods: We searched electronic databases and included studies meeting inclusion criteria. The genetic associations of four common OPG variants, A163G, T245G, T950C, and G1181C, with osteoporosis risk were explored. Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated for multiple genetic models. Subgroup analyses including ethnicity, gender, menopausal status, sample size, and control source were also performed. Results: Twenty-six studies comprising 4879 osteoporosis cases and 5708 controls were included. The A163G variant was found to be significantly associated with an increased risk of osteoporosis under both the allelic (G vs. A: OR = 1.45, 95% CI 1.29-1.64, p < 0.001) and dominant models (GG+GA vs. AA: OR = 1.48, 95% CI 1.29-1.70, p < 0.001). Significant associations were also found between the T245G variant and osteoporosis risk. In addition, we observed a reduced risk of osteoporosis in women with the CC genotype at T950C (OR = 0.76, 95% CI 0.64-0.89, p = 0.001) and among Caucasians with the GG or CG genotypes at the G1181C locus (OR = 0.78, 95% CI 0.64-0.94, p = 0.010). In postmenopausal women, only the GG/GA genotypes at the A163G variant were more predisposed to osteoporosis (OR = 1.31, 95% CI 1.00-1.71), whereas CC/CG carriers of G1181C locus may have reduced risk (OR = 0.83, 95% CI 0.66-1.03). Conclusions: Common variants of the OPG gene are associated with osteoporosis risk, especially in the Caucasian population and in the female subgroup. These genetic markers could potentially be used as predictive markers for osteoporosis.

Structural characteristics and enhanced biological activities of partially degraded arabinogalactan from larch sawdust.

Larch arabinogalactan (AG), extracted from Larix gmelinii sawdust, was depolymerized by H2O2 oxidation and purified by gel column to yield a novel degraded fraction (AGD2). The structural analysis indicated AGD2 had lower arabinose content and molecular weight compared with AG, in which the ratio of galactose and arabinose was changed from 7:3 to 16:1, the molecular weight was decreased from 50.2 kDa to 3.7 kDa, and the chain conformation spread from highly branched structure to flexible strand. It was one kind of ß-D-(1 â†’ 3)-galactan with fewer ß-D-(1 â†’ 6)-Galp side branches at O-6 position. Further, the results of the Gal-3 binding and immunomodulatory assay suggested that the unbinding force of AGD2 onto Gal-3 was as twice as AG to be 76 ± 11 pN at the loading rate of 0.15 µm/s. It could better promote the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1ß) than AG in a dose-dependent manner.

SCAR makers and multiplex PCR-based rapid molecular typing of Lentinula edodes strains.

Lentinula edodes is the second most important cultivated mushroom worldwide, the most commercial strains have been identified only through traditional phenotypic analysis. In this study, a simple rapid PCR-based molecular method was developed for distinguishing commercial strains of L. edodes by developing specific sequence characterized amplified region (SCAR) markers and establishing multiplex PCR assays with the SCAR primers. Derived from the randomly amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) techniques, 10 informative SCAR markers were generated from 10 polymorphic RAPD and SRAP bands. The differences in SCAR phenotypes among different strains made these SCAR markers potentially useful to characterize 6 strains and identify them from other studied strains. Moreover, different SCAR phenotypes also made the other 17 studied strains to be divided into four distinguishable groups. The multiplex PCR assays were further established for the joint use of some SCAR markers efficiently. Compared with some identification methods reported previously, the special feature of this new molecular method is technically rapid and convenient in the practical use and suitable for analyzing large numbers of samples. Thus, the simple rapid PCR-based molecular method can be used as a helpful assistant tool for the lentinula industry. To our knowledge, this study is the first to describe a development of a new SCAR maker-based multiplex PCR assay for rapid molecular typing of edible mushroom.

Structural characterization and hypoglycemic activity of an intracellular polysaccharide from Sanghuangporus sanghuang mycelia.

A neutral polysaccharide (SSIPS1) was isolated and purified from cultured mycelia of Sanghuangporus sanghuang by DEAE Sepharose Fast Flow and Sephacryl S-100 columns. Basic monosaccharide composition indicated that SSIPS1 was mainly composed of d-glucose. The results of methylation and 2D-NMR analysis suggested that the glycosidic linkages of SSIPS1 were elucidated to consisted of 1,4-linked α-d-glucopyranose (Glcp) residues with two branched points at O-6. The two branches were composed of 1,4-linked α-D-Glcp terminated with α-D-Glcp, 1,4-linked α-D-Glcp and 1,4-linked ß-Galp terminated by α-D-Glcp. Moreover, its chain conformation was revealed to present a flexible chain conformation in 0.1 NaNO3 with a hydrodynamic radius and radius of gyration of 3.26 and 6.45 nm by multi-angle laser light scattering, with a single chain of 0.559 nm observed by atomic force microscopy. Further, SSIPS1 exhibited a potential inhibitory activity against α-amylase and α-glucosidase, and it had hypoglycemic effects on in vitro insulin resistance of HepG2 cells as well.

Conformational properties and biological activities of α-D-mannan from Sanghuangporus sanghuang in liquid culture.

Sanghuang is a well-known edible and medicinal fungus consumed in Asia for centuries. In the present study, a novel exopolysaccharide named as mannan (SSEPS2) was isolated from the liquid culture broth of Sanghuangporus sanghuang by using ethanol precipitation, anion-exchange chromatography, and size-exclusion chromatography, which was exclusively composed of D-mannose with the molecular weight 9.43 × 104 g/mol. The structural analysis suggested that SSEPS2 consisted of 1,3-linked and 1,2-linked α-D-mannopyranose (Manp), with substitution at O-6 of 1,2-linked α-D-Manp by 1,6-linked α-D-Manp residues and terminal α-D-Manp residues. The exponent of α (0.58) indicated that SSEPS2 existed in a flexible chain conformation, with a coil-like structure in 0.1 M NaNO3 at 25 °C, which was further confirmed by the atomic force microscopy images and a three-dimensional molecular model. It exhibited potential antitumor activity against the growth of HepG2 (human hepatoma) and MCF-7 cell lines in vitro. The IC50 values for inhibiting HepG-2 cells and MCF-7 cells proliferation were 365 and 340 µg/mL, which showed its potential application in the development of anticancer therapeutics.

Multifactorial Deep Learning Reveals Pan-Cancer Genomic Tumor Clusters with Distinct Immunogenomic Landscape and Response to Immunotherapy.

PURPOSE: Tumor genomic features have been of particular interest because of their potential impact on the tumor immune microenvironment and response to immunotherapy. Due to the substantial heterogeneity, an integrative approach incorporating diverse molecular features is needed to characterize immunologic features underlying primary resistance to immunotherapy and for the establishment of novel predictive biomarkers. EXPERIMENTAL DESIGN: We developed a pan-cancer deep machine learning model integrating tumor mutation burden, microsatellite instability, and somatic copy-number alterations to classify tumors of different types into different genomic clusters, and assessed the immune microenvironment in each genomic cluster and the association of each genomic cluster with response to immunotherapy. RESULTS: Our model grouped 8,646 tumors of 29 cancer types from The Cancer Genome Atlas into four genomic clusters. Analysis of RNA-sequencing data revealed distinct immune microenvironment in tumors of each genomic class. Furthermore, applying this model to tumors from two melanoma immunotherapy clinical cohorts demonstrated that patients with melanoma of different genomic classes achieved different benefit from immunotherapy. Interestingly, tumors in cluster 4 demonstrated a cold immune microenvironment and lack of benefit from immunotherapy despite high microsatellite instability burden. CONCLUSIONS: Our study provides a proof for principle that deep learning modeling may have the potential to discover intrinsic statistical cross-modality correlations of multifactorial input data to dissect the molecular mechanisms underlying primary resistance to immunotherapy, which likely involves multiple factors from both the tumor and host at different molecular levels.

In situ reduction of silver nanoparticles by gelatin to obtain porous silver nanoparticle/chitosan composites with enhanced antimicrobial and wound-healing activity.

The identification of materials with beneficial properties for wound healing is a major research goal. In this study, gelatin was used as a reducing agent and stabilizer to restore silver nanoparticles (AgNPs) in situ, which were mixed with chitosan (CS), crosslinked with tannic acid, and then freeze-dried to obtain a new composite Gelatin/CS/Ag. Gelatin/CS/Ag has a dense pore structure with a pore size of about 100-250 µm. The pores were interconnected. The existence of AgNPs was proven by UV visible spectrophotometry, XRD, and electron microscopy. Gelatin/CS/Ag exhibited good mechanical properties, water absorption, and moisture retention. The material was evaluated in antibacterial experiments, and a good inhibitory effect of Gelatin/CS/Ag was observed. Gelatin/CS/Ag co-cultured with L929 cells did not show cytotoxicity. Finally, Gelatin/CS/Ag promoted wound healing and showed good biocompatibility. In summary, Gelatin/CS/Ag has promising antibacterial and wound healing properties.

Silver nanoparticles in situ synthesized by polysaccharides from Sanghuangporus sanghuang and composites with chitosan to prepare scaffolds for the regeneration of infected full-thickness skin defects.

In recent years, silver nanoparticles have widely been used in antibacterial dressings to solve antibiotic resistance problems. However, traditional methods for reducing silver nanoparticles are usually toxic. To overcome this problem, Sanghuangporus sanghuang polysaccharides (FSHPs) were used as a green reducing agent to prepare silver nanoparticles (AgNPs) with a size of 3-35 nm. The FSHPs­silver nanoparticles (FSHPs-Ag) composite with chitosan solution were then freeze-dried to obtain a porous sponge dressing of chitosan-FSHPs-Ag (CS-FSHPs-Ag). The internal pores of CS-FSHPs-Ag were between 50 and 100 µm and had good swelling and water retention properties, which could provide a moist environment for wounds. Based on the experimental results, the appropriate concentration of AgNPs required for CS-FSHPs-Ag to inhibit Escherichia coli and Staphylococcus aureus was determined. Moreover, there was no statistically significant difference between the material treatment and the blank control group, indicating that the material almost showed no toxicity to L929 cells. Finally, this material was used for dressing animal wounds. The results showed that the CS-FSHPs-Ag promoted wound contraction and internal tissue growth better than the wounds treated with Aquacel® Ag, which indicated that the CS-FSHPs-Ag has a great potential as an ideal wound dressing material.