Royal jelly and its hormonal effects in breast cancer: a literature review.

BACKGROUND: Breast cancer is the most common cancer in women which can be cured in most individuals with early-stage non-metastatic disease. Imbalance in estrogen signaling pathways and propagating levels of estrogens has important roles in breast cancer development. Targeting the estrogen receptor signaling pathway is linked to breast cancer treatment. Royal jelly is one of the bee products containing 10-hydroxy-2-decenoic acid, a structure similar to mammalian estrogen, allowing it to attach to estrogen receptors. It is considered as a general tonic and immunomodulator which may be helpful in reducing the side effects of cancer treatments. Currently, there are controversial data regarding the pros and cons of royal jelly in cancer. Here we provide an overview of the effects of royal jelly on sex hormones and its possible role in breast cancer. METHODS: Electronic databases including PubMed, Scopus, and Web of Science were searched with the search terms royal jelly, cancer, and sexual hormones. All preclinical and clinical studies regarding the hormonal effects of royal jelly were included. RESULTS: According to the collected preclinical data, consumption of royal jelly at daily doses below 200 mg/kg can be useful to decrease the risk of breast cancer since it reduces the serum level of estrogen; whereas increases progesterone, which subsequently decreases the expression of ERs on the ER-positive cells. CONCLUSION: Future clinical studies are essential to confirm the safe dose of royal jelly as an adjuvant therapy in breast cancer.

Delivery Systems for Plasma-reactive Species and their Applications in the Field of Biomedicine.

Cold atmospheric plasma (CAP) is an ionized matter with potential applications in various medical fields, ranging from wound healing and disinfection to cancer treatment. CAP's clinical usefulness stems from its ability to act as an adjustable source of reactive oxygen and nitrogen species (RONS), which are known to function as pleiotropic signaling agents within cells. Plasma-activated species, such as RONS, have the potential to be consistently and precisely released by carriers, enabling their utilization in a wide array of biomedical applications. Furthermore, understanding the behavior of CAP in different environments, including water, salt solutions, culture medium, hydrogels, and nanoparticles, may lead to new opportunities for maximizing its therapeutic potential. This review article sought to provide a comprehensive and critical analysis of current biomaterial approaches for the targeted delivery of plasma-activated species in the hope to boost therapeutic response and clinical applicability.

Layer-by-Layer Deposition of Regenerated Silk Fibroin─An Approach to the Surface Coating of Biomedical Implant Materials.

Biomaterials and coating techniques unlock major benefits for advanced medical therapies. Here, we explored layer-by-layer (LbL) deposition of silk fibroin (SF) by dip coating to deploy homogeneous films on different materials (titanium, magnesium, and polymers) frequently used for orthopedic and other bone-related implants. Titanium and magnesium specimens underwent preceding plasma electrolytic oxidation (PEO) to increase hydrophilicity. This was determined as surface properties were visualized by scanning electron microscopy and contact angle measurements as well as Fourier transform infrared spectroscopy (FTIR) analysis. Finally, biological in vitro evaluations of hemocompatibility, THP-1 cell culture, and TNF-α assays were conducted. A more hydrophilic surface could be achieved using the PEO surface, and the contact angle for magnesium and titanium showed a reduction from 73 to 18° and from 58 to 17°, respectively. Coating with SF proved successful on all three surfaces, and coating thicknesses of up to 5.14 µm (±SD 0.22 µm) were achieved. Using FTIR analysis, it was shown that the insolubility of the material was achieved by post-treatment with water vapor annealing, although the random coil peak (1640-1649 cm-1) and the α-helix peak (at 1650 cm-1) were still evident. SF did not change hemocompatibility, regardless of the substrate, whereas the PEO-coated materials showed improved hemocompatibility. THP-1 cell culture showed that cells adhered excellently to all of the tested material surfaces. Interestingly, SF coatings induced a significantly higher amount of TNF-α for all materials, indicating an inflammatory response, which plays an important role in a variety of physiological processes, including osteogenesis. LbL coatings of SF are shown to be promising candidates to modulate the body's immune response to implants manufactured from titanium, magnesium, and polymers. They may therefore facilitate future applications for bioactive implant coatings. However, further in vivo studies are needed to confirm the proposed effects on osteogenesis in a physiological environment.

Do Titanium Dioxide Particles Stimulate Macrophages to Release Proinflammatory Cytokines and Increase the Risk for Peri-implantitis?

PURPOSE: Titanium dioxide (TiO2) particles detached from titanium dental implants by tribocorrosion can be phagocytosed by macrophages, releasing various proinflammatory cytokines at the implant sites that may trigger peri-implantitis. The study objective was to measure the association between peri-implantitis and the presence of non-allergy-related proinflammatory cytokines associated with TiO2 particles. METHODS: The investigators implemented a retrospective cross-sectional study and enrolled a sample of 60 subjects from a dental practice. Subjects were excluded if the plaque index was grade 3 (Silness and Löe). The predictor variable was a positive or negative TiO2 stimulation test, an in vitro macrophage proinflammatory response test. The outcome variable was peri-implantitis status defined as present or absent. Three groups were considered: control group with 20 patients without dental implants (group 1), 2 groups of patients with titanium dental implants, one without peri-implantitis (group 2), and the other with peri-implantitis (group 3) (n = 20 each). For patients with implants, depth of the gingival pockets of the implants were measured, and existing bleeding and suppuration were determined to assess peri-implantitis. Radiographs were taken if one or more factors applied to confirm the diagnosis of peri-implantitis. Further covariates were age, sex, duration of implant wear, and number of implants which were analyzed descriptively. Inferential analyses were undertaken using χ2 test, Kruskal-Wallis-, Wilcoxon-two-sample tests, and logistic regressions. RESULTS: The sample was composed of 35 female and 25 male patients with a mean age of 54.2 years (standard deviation = 14.76). The overall TiO2 stimulation test positivity frequency was 28.3% and were 30.0%, 5.0%, and 50.0% in the control, implants without peri-implantitis, and implants with peri-implantitis groups. No statistically significant differences could be seen in the frequencies of the TiO2 stimulation test results between control group and combined groups 2 and 3 (P-value = .84). The risk for positive TiO2 patients with a titanium implant of developing peri-implantitis was statistically significant and higher compared to negative TiO2 patients (odds ratio, 19.0 with 95% confidence interval [2.12,170.38]; P-value< .01). CONCLUSIONS: The data in this study showed a statistically significant relationship between a positive TiO2 stimulation test and peri-implantitis. Further studies with larger numbers of subjects are recommended to confirm this result.

Chemical modification of acellular fish skin as a promising biological scaffold by carbodiimide cross-linker for wound healing.

Biological matrices can be modified with cross-linkers to improve some of their characteristics as scaffolds for tissue engineering. In this study, chemical cross-linker 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) was used with different ratios (5, 10, 20, 30, and 40 mM) to improve properties such as mechanical strength, denaturation temperature, and degradability of the acellular fish skin as a biological scaffold for tissue engineering applications. Morphological analysis showed that the use of cross-linker at low concentrations had no effect on the structure and textiles of the scaffold, while increasing mechanical strength, denaturation temperature, and degradation time. Cytotoxicity and cellular studies showed that the optimal cross-linker concentration did not significantly affect cell viability as well as cell adhesion. In general, utilising the carbodiimide cross-linker with the optimal ratio can improve the characteristics and function of the biological tissues such as acellular fish skin.

Silk proteins in reconstructive surgery: Do they possess an inherent antibacterial activity? A systematic review.

The field of reconstructive surgery encompasses a wide range of surgical procedures and regenerative approaches to treat various tissue types. Every surgical procedure is associated with the risk of surgical site infections, which are not only a financial burden but also increase patient morbidity. The surgical armamentarium in this area are biomaterials, particularly natural, biodegradable, biocompatible polymers, including the silk proteins fibroin (SF) and sericin (SS). Silk is known to be derived from silkworms and is mainly composed of 60-80% fibroin, which provides the structural form, and 15-35% sericin, which acts as a glue-like substance for the SF threads. Silk proteins possess most of the desired properties for biomedical applications, including biocompatibility, biodegradability, minimal immunogenicity, and tunable biomechanical behaviour. In an effort to alleviate or even prevent infections associated with the use of biomaterials in surgery, antibacterial/antimicrobial properties have been investigated in numerous studies. In this systematic review, the following question was addressed: Do silk proteins, SF and SS, possess an intrinsic antibacterial property and how could these materials be tailored to achieve such a property?

Viral inactivation by light.

Nowadays, viral infections are one of the greatest challenges for medical sciences and human society. While antiviral compounds and chemical inactivation remain inadequate, physical approaches based on irradiation provide new potentials for prevention and treatment of viral infections, without the risk of drug resistance and other unwanted side effects. Light across the electromagnetic spectrum can inactivate the virions using ionizing and non-ionizing radiations. This review highlights the anti-viral utility of radiant methods from the aspects of ionizing radiation, including high energy ultraviolet, gamma ray, X-ray, and neutron, and non-ionizing photo-inactivation, including lasers and blue light.

Antibacterial properties of functionalized silk fibroin and sericin membranes for wound healing applications in oral and maxillofacial surgery.

Oral wounds are among the most troublesome injuries which easily affect the patients' quality of life. To date, the development of functional antibacterial dressings for oral wound healing remains a challenge. In this regard, we investigated antibacterial silk protein-based membranes for the application as wound dressings in oral and maxillofacial surgery. The present study includes five variants of casted membranes, i.e., i) membranes-silver nanoparticles (CM-Ag), ii) membranes-gentamicin (CM-G), iii) membranes-control (without functionalization) (CM-C), iv) membranes-silk sericin control (CM-SSC), and v) membranes-silk fibroin/silk sericin (CM-SF/SS), and three variants of nonwovens, i.e., i) silver nanoparticles (NW-Ag), ii) gentamicin (NW-G), iii) control (without functionalization) (NW-C). The surface structure of the samples was visualized with scanning electron microscopy. In addition, antibacterial testing was accomplished using agar diffusion assay, colony forming unit (CFU) analysis, and qrt-PCR. Following antibacterial assays, biocompatibility was evaluated by cell proliferation assay (XTT), cytotoxicity assay (LDH), and live-dead assay on L929 mouse fibroblasts. Findings indicated significantly lower bacterial colony growth and DNA counts for CM-Ag with a reduction of bacterial counts by 3log levels (99.9% reduction) in CFU and qrt-PCR assay compared to untreated control membranes (CM-C and CM-SSC) and membranes functionalized with gentamicin (CM-G and NW-G) (p < 0.001). Similarly, NW-G yielded significantly lower DNA and colony growth counts compared to NW-Ag and NW-C (p < 0.001). In conclusion, CM-Ag represented 1log level better antibacterial activity compared to NW-G, whereas NW-G showed better cytocompatibility for L929 cells. As data suggest, these two membranes have the potential of application in the field of bacteria-free oral wound healing. However, provided that loading strategy and cytocompatibility are adjusted according to the antibacterial agents' characteristic and fabrication technique of the membranes.

Tissue Adhesives in Reconstructive and Aesthetic Surgery-Application of Silk Fibroin-Based Biomaterials.

Tissue adhesives have been successfully used in various kind of surgeries such as oral and maxillofacial surgery for some time. They serve as a substitute for suturing of tissues and shorten treatment time. Besides synthetic-based adhesives, a number of biological-based formulations are finding their way into research and clinical application. In natural adhesives, proteins play a crucial role, mediating adhesion and cohesion at the same time. Silk fibroin, as a natural biomaterial, represents an interesting alternative to conventional medical adhesives. Here, the most commonly used bioadhesives as well as the potential of silk fibroin as natural adhesives will be discussed.

3D Bio-printing For Skin Tissue Regeneration: Hopes and Hurdles.

For many years, discovering the appropriate methods for the treatment of skin irritation has been challenging for specialists and researchers. Bio-printing can be extensively applied to address the demand for proper skin substitutes to improve skin damage. Nowadays, to make more effective biomimicry of natural skin, many research teams have developed cell-seeded bio-inks for bioprinting of skin substitutes. These loaded cells can be single or co-cultured in these structures. The present review gives a comprehensive overview of the methods, substantial parameters of skin bioprinting, examples of in vitro and in vivo studies, and current advances and challenges in skin tissue engineering.

Applications of bacteria and their derived biomaterials for repair and tissue regeneration.

Microorganisms such as bacteria and their derived biopolymers can be used in biomaterials and tissue regeneration. Various methods have been applied to regenerate damaged tissues, but using probiotics and biomaterials derived from bacteria with improved economic-production efficiency and highly applicable properties can be a new solution in tissue regeneration. Bacteria can synthesize numerous types of biopolymers. These biopolymers possess many desirable properties such as biocompatibility and biodegradability, making them good candidates for tissue regeneration. Here, we reviewed different types of bacterial-derived biopolymers and highlight their applications for tissue regeneration.

A concise review on drug-loaded electrospun nanofibres as promising wound dressings.

The diversity of wound types has gathered momentum to develop a wide range of wound dressings to improve different aspects of the wound healing process. Wound healing is a dynamic, complex and highly regulated mechanism of tissue repair and regeneration. The wound dressing should encourage regeneration and prevent possible infection or scaring. Wound dressings are different from the bandages as they come in direct contact with the wound and are used to absorb exudates and accelerate healing. Wound dressings can have a variety of functions, depending upon the type, severity, and position of the wound. In this review, we have studied the properties of nanofibrous wound dresses and possible approaches to load biological components into them for wound healing improvement.