Enhancement of anti-tumor activity of gamma-irradiated silk fibroin via immunomodulatory effects

NFL-TBS.40-63 Peptide Gold Complex Nanovector: A Novel Therapeutic Approach to Increase Anticancer Activity by Breakdown of Microtubules in Pancreatic Adenocarcinoma (PDAC)

The role of the NFL-TBS.40-63 peptide is to destroy the microtubule network of target glioma cancer cells. Recently, we have conceived a gold-complex biotinylated NFL-TBS.40-63 (BIOT-NFL) to form a hybrid gold nanovector (BIOT-NFL-PEG-AuNPs). This methodology showed, for the first time, the ability of the BIOT-NFL-PEG-AuNPs to target the destruction of pancreatic cancer cells (PDAC) under experimental conditions, as well as detoxification and preclinical therapeutic efficacy regulated by the steric and chemical configuration of the peptide. For this aim, a mouse transplantation tumor model induced by MIA-PACA-2 cells was applied to estimate the therapeutic efficacy of BIOT-NFL-PEG-AuNPs as a nanoformulation. Our relevant results display that BIOT-NFL-PEG-AuNPs slowed the tumor growth and decreased the tumor index without effects on the body weight of mice with an excellent antiangiogenic effect, mediated by the ability of BIOT-NFL-PEG-AuNPs to alter the metabolic profiles of these MIA-PACA-2 cells. The cytokine levels were detected to evaluate the behavior of serum inflammatory factors and the power of BIOT-NFL-PEG-AuNPs to boost the immune system.

The Effect of Sterilization on the Characteristics of Silk Fibroin Nanoparticles

In recent years, silk fibroin nanoparticles (SFNs) have been consolidated as drug delivery systems (DDSs) with multiple applications in personalized medicine. The design of a simple, inexpensive, and scalable preparation method is an objective pursued by many research groups. When the objective is to produce nanoparticles suitable for biomedical uses, their sterility is essential. To achieve sufficient control of all the crucial stages in the process and knowledge of their implications for the final characteristics of the nanoparticles, the present work focused on the final stage of sterilization. In this work, the sterilization of SFNs was studied by comparing the effect of different available treatments on the characteristics of the nanoparticles. Two different sterilization methods, gamma irradiation and autoclaving, were tested, and optimal conditions were identified to achieve the sterilization of SFNs by gamma irradiation. The minimum irradiation dose to achieve sterilization of the nanoparticle suspension without changes in the nanoparticle size, polydispersity, or Z-potential was determined to be 5 kiloGrays (kGy). These simple and safe methods were successfully implemented for the sterilization of SFNs in aqueous suspension and facilitate the application of these nanoparticles in medicine.

Selenium-rich royal jelly inhibits hepatocellular carcinoma through PI3K/AKT and VEGF pathways in H22 tumor-bearing mice

Royal jelly (RJ) and selenium (Se)-rich foods have well-known health benefits that are attributable to a broad range of pharmacological effects including antioxidant, anti-tumor, and immunoregulatory activities. However, the physiological effects of Se-rich RJ, which is produced by feeding Apis mellifera (Hymenoptera: Apidae) sodium selenite sucrose solution, are not well understood. The anti-hepatoma activity and mechanism of Se-rich RJ in H22 tumor-bearing mice were investigated in the current study. The findings showed that the content of organic and inorganic Se in Se-rich RJ was significantly higher than that in RJ. Furthermore, interleukin-2 (IL-2) levels and tumor necrosis factor-α (TNF-α) production in serum were increased and the malondialdehyde (MDA) content in liver was decreased in mice fed RJ and Se-rich RJ. 16SrRNA sequencing and serum untargeted metabolomics showed that RJ and Se-rich RJ could modulate the gut microbiota, and fisetin and l-glutathione oxidized were the main anti-tumor components in RJ and Se-rich RJ. Further analysis showed 11-deoxy prostaglandin F1β was the specific anti-tumor metabolite in mice treated with Se-rich RJ compared with RJ. The results indicated that RJ and Se-rich RJ could inhibit the expression of PI3K and phosphorylation of AKT, induce cell apoptosis through the activation of caspase-9 and caspase-3, and regulate Bcl-2/Bax expression. RJ and Se-rich RJ also inhibited the expression of COX-2 and VEGF. To summarize, the findings clearly demonstrate that Se-rich RJ could inhibit tumor growth by inducing apoptosis and inhibiting angiogenesis as well as exhibit anti-tumor effects by improving immune function and antioxidant activities. The results indicated that Se-rich RJ could be a potential functional food for the management and prevention of cancer.

Effect of Silk Fibroin Biomaterial Coating on Cell Viability and Intestinal Adhesion of Probiotic Bacteria

Probiotics can be processed into a powder, tablet, or capsule form for easy intake. They are exposed to frequent stresses not only during complex processing steps, but also in the human body after intake. For this reason, various coating agents that promote probiotic bacterial stability in the intestinal environment have been developed. Silk fibroin (SF) is a material used in a variety of fields from drug delivery systems to enzyme immobilization and has potential as a coating agent for probiotics. In this study, we investigated this potential by coating probiotic strains with 0.1% or 1% water-soluble calcium (WSC), 1% SF, and 10% trehalose. Under simulated gastrointestinal conditions, cell viability, cell surface hydrophobicity, and cell adhesion to intestinal epithelial cells were then measured. The survival ratio after freeze-drying was highest upon addition of 0.1% WSC. The probiotic bacteria coated with SF showed improved survival by more than 10.0% under simulated gastric conditions and 4.8% under simulated intestinal conditions. Moreover, the cell adhesion to intestinal epithelial cells was elevated by 1.0-36.0%. Our results indicate that SF has positive effects on enhancing the survival and adhesion capacity of bacterial strains under environmental stresses, thus demonstrating its potential as a suitable coating agent to stabilize probiotics throughout processing, packaging, storage and consumption.

Dry Surface Treatments of Silk Biomaterials and Their Utility in Biomedical Applications

Silk-based materials are widely used in biomaterial and tissue engineering applications due to their cytocompatibility and tunable mechanical and biodegradation properties. Aqueous-based processing techniques have enabled the fabrication of silk into a broad range of material formats, making it a highly versatile material platform across multiple industries. Utilizing the full potential of silk in biomedical applications frequently requires modification of silk's surface properties. Dry surface modification techniques, including irradiation and plasma treatment, offer an alternative to the conventional wet chemistry strategies to modify the physical and chemical properties of silk materials without compromising their bulk properties. While dry surface modification techniques are more prevalent in textiles and sterilization applications, the range of modifications available and resultant changes to silk materials all point to the utility of dry surface modification for the development of new, functional silk biomaterials. Dry surface treatment affects the surface chemistry, secondary structure, molecular weight, topography, surface energy, and mechanical properties of silk materials. This Review describes and critically evaluates the effect of physical dry surface modification techniques, including irradiation and plasma processes, on silk materials and discusses their utility in biomedical applications, including recent examples of modulation of cell/protein interactions on silk biomaterials, in vivo performance of implanted biomaterials, and applications in material biofunctionalization and lithographic surface patterning approaches.

Effect of Dietary Silk Peptide on Obesity, Hyperglycemia, and Skeletal Muscle Regeneration in High-Fat Diet-Fed Mice

Obesity is associated with excess body fat accumulation that can cause hyperglycemia and reduce skeletal muscle function and strength, which characterize the development of sarcopenic obesity. In this study, we aimed to determine the mechanism whereby acid-hydrolyzed silk peptide (SP) prevents high-fat diet (HFD)-induced obesity and whether it regulates glucose uptake and muscle differentiation using in vivo and in vitro approaches. Our findings demonstrate that SP inhibits body mass gain and the expression of adipogenic transcription factors in visceral adipose tissue (VAT). SP also had an anti-diabetic effect in VAT and skeletal muscle because it upregulated glucose transporter type 4 (GLUT4) and uncoupling protein 3 (UCP3) expression. Furthermore, SP reduced ubiquitin proteasome and promoted myoblast determination protein 1 (MyoD)/myogenic factor 4 (myogenin) expression, implying that it may have potential for the treatment of obesity-induced hyperglycemia and obesity-associated sarcopenia.

Gamma-Irradiated Chrysin Improves Anticancer Activity in HT-29 Colon Cancer Cells Through Mitochondria-Related Pathway

Irradiation technology can improve the biological activities of natural molecules through a structural modification. This study was conducted to investigate the enhancement of the anticancer effects of chrysin upon exposure to gamma irradiation. Gamma irradiation induces the production of new radiolytic peaks simultaneously with the decrease of the chrysin peak, which increases the cytotoxicity in HT-29 human colon cancer cells. An isolated chrysin derivative (CM1) exhibited a stronger apoptotic effect in HT-29 cells than intact chrysin. The apoptotic characteristics induced by CM1 in HT-29 cells was mediated through the intrinsic signaling pathway, including the excessive production of included reactive oxygen species, the dissipation of the mitochondrial membrane potential, regulation of the B cell lymphoma-2 family, activation of caspase-9, 3, and cleavage of poly (adenosine diphosphate-ribose) polymerase. Our findings suggest that CM1 can be a potential anticancer candidate for the treatment of colon cancer.

Hesperidin structurally modified by gamma irradiation induces apoptosis in murine melanoma B16BL6 cells and inhibits both subcutaneous tumor growth and metastasis in C57BL/6 mice

Hesperidin is a flavonoid which occurs in citrus fruits. Hesperidin was gamma-irradiated at doses of 0, 30, 70, and 150 kGy. Gamma irradiation induced a decreased hesperidin peak, and a new radiolytic peak that gradually increased up to 150 kGy. The new radiolytic peak was fractionated, and the fractionated hesperidin derivative was used for subsequent experiments. Hesperidin gamma-irradiated at 150 kGy was toxic toward B16BL6 cells, but not toward bone marrow-derived macrophages. This cytotoxicity was exerted via induction of apoptosis, as reflected by the high population of double-positive cells, increased sub-G1 phase cells, depolarization of matrix metalloproteinase, production of reactive oxygen species, weakness of cell adhesion, changes in cell morphology, and inhibition of B16BL6 cell migration. Furthermore, 150 kGy gamma-irradiated hesperidin decreased the expression of Bcl-2 and pro-caspases-3 and -9, increased the expression of Bax and cytosolic cytochrome c, and increased the cleavage of poly ADP ribose polymerase. In vitro mechanistic study revealed that 150 kGy gamma-irradiated hesperidin achieved significantly greater inhibition of lung metastasis and growth of melanoma B16BL6 cells in C57BL/6 mice than non-irradiated intact hesperidin did. These results suggest that the structural modification of hesperidin induced by gamma irradiation could facilitate the development of anti-cancer drugs.

The phenolic profiles of Radix Tetrastigma after solid phase extraction (SPE) and their antitumor effects and antioxidant activities in H22 tumor-bearing mice

Photographic illustrations of phenolic profiles, antitumor effects and antioxidant activities of Radix Tetrastigma after solid phase extraction (SPE) in H22 tumor-bearing mice.

Production of immunoregulatory polysaccharides from Crassostrea hongkongensis and their positive effects as a nutrition factor in modulating the effectiveness and toxicity of 5-FU chemotherapy in mice

Chemotherapy is generally accompanied by undesirable side effects, such as immunosuppression and malnutrition, which reduce tolerance to cancer therapies. Prior studies have shown that immunonutrition improves the clinical outcomes of cancer patients. In this study, immunoregulatory polysaccharides from Crassostrea hongkongensis were included in a nutrition formula that was administered to S180 tumor-bearing mice in combination with 5-fluorouracil (5-FU) treatment. The C30-60% fraction of the polysaccharides was characterized as a branched polysaccharide, with a high amount of d-glucose (96.76% of the total) and the highest uronic acid and sulfate groups' content among all of the polysaccharide fractions. The C30-60% polysaccharide fraction showed a maximal proliferative effect on RAW264.7 cells and T lymphocytes at a concentration of 0.0391 mg mL(-1) and 0.0781 mg mL(-1), respectively. Moreover, the combination treatment of the C30-60% polysaccharide-based nutrition formula (OPNF) with the administration of 5-FU effectively inhibited the growth of tumors and notably increased the leucocyte and lymphocyte counts in S180 tumor-bearing mice. In addition, a slight increase in the erythrocyte and hemoglobin values was observed in the mice treated with the combination of OPNF and 5-FU. These results suggest that supplementation with a C30-60%-based enteral formula would be beneficial for patients undergoing chemotherapy with 5-FU.

Increased proapoptotic activity of electron beam irradiated doxorubicin and epirubicin in multidrug-resistant human leukemic cells

This study evaluated the effect of electron beam irradiation on the cytotoxic activity of anthracycline antibiotics such as doxorubicin (DOX), epirubicin (EPI), and dunorubicin (DAU) in human acute lymphoblastic leukemia cell line CCRF-CEM and its multidrug-resistant variant CCRF-VCR1000 cell line characterized by the overexpression of ABCB1 gene. Drugs were irradiated at doses of 10 and 25 kGy. Data from EPR studies proved that the highest concentration of free radicals was found in DOX and that the number of stable free radicals is always greater after irradiation. In in vitro studies, a higher cytotoxic activity of irradiated DOX and EPI in multidrug-resistant CCRF-VCR1000 cells was observed. This tendency was maintained during the storage at 4 °C for 90 days. Changes in CCRF-CEM cells' viability were not dependent on the irradiation status and its dose and were only drug-concentration dependent in all measurement time points. It was proved that increased potency of 25 kGy e-beam irradiated drugs results from their enhanced proapoptotic activity. Apoptotic cell death observed in CCRF-VCR1000 cells treated with irradiated drugs was caspase-8, -9, and -3 dependent and related to the increased Bax/Bcl-2 ratio. No significant differences in the effects of irradiated and non-irradiated drugs on p53 and NFκB transcription factor level and their translocation to the nucleus were noted. Increased activity of the irradiated drugs was not dependent on ABCB1 level.

Anti-inflammatory effect of gamma-irradiated genistein through inhibition of NF-κB and MAPK signaling pathway in lipopolysaccharide-induced macrophages

Genistein was irradiated with γ-irradiation at doses of 0, 10, 30, 50, 100, and 150 kGy. We observed that the decrease in the genistein peak after gamma irradiation was concomitant with the appearance of several new peaks. 150 kGy gamma-irradiated genistein did not exert cytotoxicity in macrophages, and inhibited inducible nitric oxide synthase-mediated nitric oxide production and pro-inflammatory cytokines level, such as tumor necrosis factor-α, interleukin-6 and interleukin-1β, in lipopolysaccharide (LPS)-induced macrophages. The treatment of LPS-stimulated macrophages with 150 kGy gamma-irradiated genistein resulted in a significant decrease in cyclooxygenase-2 levels, as well as the expression of cell surface molecules, such as CD80 and CD86. Furthermore, we also found that the anti-inflammatory action of 150 kGy gamma-irradiated genistein occurred through an inhibition of mitogen-activated protein kinases (extracellular signal-regulated kinase 1/2, p38 and c-Jun N-terminal kinase) and nuclear factor-κB signaling pathways based on a toll-like receptor 4 in macrophages, which may be speculated that several radiolysis products of genistein transformed by gamma-irradiation induce the inhibition of pro-inflammatory mediators. From these findings, it seems likely that gamma-irradiated genistein could play a potent role in the treatment of inflammatory disease as a value-added product in the medical industry.

Characterization and antitumor activity of a polysaccharide from Sarcodia ceylonensis

A water-soluble polysaccharide from Sarcodia ceylonensis was obtained by using the method of water-extraction and ethanol-precipitation. The polysaccharide was further purified by chromatography on AB-8 and ADS-7 columns, yielding a pure polysaccharide termed SCP-60. The molecular weight (Mw) of SCP-60 was calculated to be 50.0 kDa, based on the calibration curve obtained with a series of Dextran T standards. The results of FT-IR indicated that the polysaccharide contains the α-configuration of sugar units. GC-MS analysis revealed that SCP-60 was mainly composed of galactose and glucose. NMR spectroscopy revealed SCP-60 had the backbone consisting of → 6)-α-Manp-(1 →, α-D-Glcp-(1 →, → 6)-α-D-Glcp-(1 → and → 6)-α-Galp-(1 →. In order to evaluate the antitumor activity in vivo of the polysaccharide, a sarcoma 180 model was used. The results showed SCP-60 had strong antitumor ability, meanwhile, SCP-60 at a high dose (100 mg/kg) could significantly increase the thymic and splenic indices of S180 mice, and strongly promote the secretion of IL-2, TNF-α and IFN-γ, increase the SOD activities and reduce the concentrations of MDA in blood. Therefore the polysaccharide SCP-60 should be explored as a novel potential antitumor drug.

Involvement of Trypsin-Digested Silk Peptides in the Induction of RAW264.7 Macrophage Activation

The activation of macrophages by trypsin-digested silk peptides was investigated by considering CD11b and CD40 expression in the RAW264.7 cell, a murine macrophage. Silk protein hydrolysates were digested with trypsin, following by centrifugal purification using the Centriprep 30k concentrator. Trypsin-digested total silk peptides and its centrifugal fractions were tested for macrophage activation in vitro. The functional peptide of fractionated silk peptides was examined by LC/MS/MS analysis. Trypsin-digested and fractionated silk peptides of more than 30 kDa induced an increase in the activation markers CD11b and CD40 in RAW264.7 cells. These results are supported by morphological changes reflecting an increase in the number of dendrites in activated cells. The fractionated silk peptides examined by LC/MS/MS contained partial peptides of Bombyx mori fibroin. These results suggest that the activation of RAW264.7 macrophages may be induced not by sericin-derived peptides but by fibroin-derived ones.

A pilot study of macrophage responses to silk fibroin particles

Silk fibroin (SF) shows promise for tissue engineering and other biomedical applications due to its excellent biocompatibility, unique biomechanical properties, and controllable biodegradability. The particulate form of SF materials may have many potential uses, including the use as a filler for tissue defects or as a controlled-release agent for drug delivery. However, many past in vivo and in vitro studies evaluating the biocompatibility and biodegradability of SF have involved bulk implants. It is essential to evaluate the inflammatory effects of SF particles before further use. In this study, two different sizes of SF particles were evaluated to assess their impact on the release of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, in comparison with lipopolysaccharide positive control stimulation. The inflammatory processes were characterized using real-time reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and light microscopy evaluations. The results indicated that small silk fibroin particles and large silk fibroin particles, in culture with RAW 264.7 murine macrophage cells for 24 h, caused up-regulation of mRNA coding for TNF-α, which indicated that both size of particles have potential inflammatory effects. There was a statistically significant increase in this up-regulation under small silk fibroin stimulation. However, the immunosorbent assay suggested that there was virtually no observed release of IL-1β, IL-6, or TNF-α, relative to the control group. The results suggest that SF particles of the chosen dimensions may have good biocompatibility in culture with RAW 264.7 murine macrophages.

Silk constructs for delivery of musculoskeletal therapeutics

Silk fibroin (SF) is a biopolymer with distinguishing features from many other bio- as well as synthetic polymers. From a biomechanical and drug delivery perspective, SF combines remarkable versatility for scaffolding (solid implants, hydrogels, threads, solutions), with advanced mechanical properties and good stabilization and controlled delivery of entrapped protein and small molecule drugs, respectively. It is this combination of mechanical and pharmaceutical features which renders SF so exciting for biomedical applications. This pattern along with the versatility of this biopolymer has been translated into progress for musculoskeletal applications. We review the use and potential of silk fibroin for systemic and localized delivery of therapeutics in diseases affecting the musculoskeletal system. We also present future directions for this biopolymer as well as the necessary research and development steps for their achievement.

Human amniotic fluid stem cells seeded in fibroin scaffold produce in vivo mineralized matrix

This study investigated the potential of amniotic fluid stem cells (AFSCs) to synthesize mineralized extracellular matrix (ECM) within different porous scaffolds of collagen, poly-D,L-lactic acid (PDLLA), and silk fibroin. The AFSCs were initially differentiated by using an osteogenic medium in two-dimensional culture, and expression of specific bone proteins and the physiologic mineral production by the AFSCs were analyzed. In particular, during differentiation process, AFSCs expressed proteins like Runt-related transcription factor 2 (Runx2), Osterix, Osteopontin, and Osteocalcin with a sequential expression, analogous to those occurring during osteoblast differentiation, and produced extracellular calcium stores. AFSCs were then cultured on three-dimensional (3D) scaffolds and evaluated for their ability to differentiate into osteoblastic cells in vivo. Stem cells were cultured in vitro for 1 week in collagen, fibroin, and PDLLA scaffolds. The effect of predifferentiation of the stem cells in scaffolds on the subsequent bone formation in vivo was determined in a rat subcutaneous model. With the addition of a third dimension, osteogenic differentiation and mineralized ECM production by AFSCs were significantly higher. This study demonstrated the strong potential of AFSCs to produce 3D mineralized bioengineered constructs in vivo and suggests that fibroin may be an effective scaffold material for functional repair of critical size bone defects.