Effects of Adipose-Derived Biogenic Nanoparticle-Associated microRNA-451a on Toll-like Receptor 4-Induced Cytokines

Extracellular vesicles (EVs) are cell-released nanoparticles that transfer biomolecular content between cells. Among EV-associated biomolecules, microRNAs (miRNAs/miRs) represent one of the most important modulators of signaling pathways in recipient cells. Previous studies have shown that EVs from adipose-derived mesenchymal stromal cells (MSCs) and adipose tissue modulate inflammatory pathways in macrophages. In this study, the effects of miRNAs that are abundant in adipose tissue EVs and other biogenic nanoparticles (BiNPs) were assessed in terms of altering Toll-like receptor 4 (TLR4)-induced cytokines. TLR-4 signaling in macrophages is often triggered by pathogen or damage-induced inflammation and is associated with several diseases. This study demonstrates that miR-451a, which is abundant in adipose tissue BiNPs, suppresses pro-inflammatory cytokines and increases anti-inflammatory cytokines associated with the TLR4 pathway. Therefore, miR-451a may be partially responsible for immunomodulatory effects of adipose tissue-derived BiNPs.

Wound Healing Activities and Potential of Selected African Medicinal Plants and Their Synthesized Biogenic Nanoparticles

In Africa, medicinal plants have been traditionally used as a source of medicine for centuries. To date, African medicinal plants continue to play a significant role in the treatment of wounds. Chronic wounds are associated with severe healthcare and socio-economic burdens despite the use of conventional therapies. Emergence of novel wound healing strategies using medicinal plants in conjunction with nanotechnology has the potential to develop efficacious wound healing therapeutics with enhanced wound repair mechanisms. This review identified African medicinal plants and biogenic nanoparticles used to promote wound healing through various mechanisms including improved wound contraction and epithelialization as well as antibacterial, antioxidant and anti-inflammatory activities. To achieve this, electronic databases such as PubMed, Scifinder® and Google Scholar were used to search for medicinal plants used by the African populace that were scientifically evaluated for their wound healing activities in both in vitro and in vivo models from 2004 to 2021. Additionally, data on the wound healing mechanisms of biogenic nanoparticles synthesized using African medicinal plants is included herein. The continued scientific evaluation of wound healing African medicinal plants and the development of novel nanomaterials using these plants is imperative in a bid to alleviate the detrimental effects of chronic wounds.

Sources of Potential Fungi Generated Biogenic Nanoparticles for the Control of Diseases Transmitting Mosquitoes: A Review

Vector mosquitoes are diseases transmitting malaria, filarial, dengue, and Japanese encephalitis are an enormous burden to public people worldwide. There is no proper vaccine for those diseases; even though malaria is significant, challenges are still waiting for successful management. Recently, fungi and fungi-derived products control mosquito larvae, pupae, and adults better than compared to plants or other microorganisms. The using fungi such as Aspergillus sp., Beauveria bassiana, Metarhizium anisopliae, Verticillium lecanii are more virulent for controlling mosquito vectors, Aedes aegypti, Anopheles stephensi, Culex quinquefasciatus. The synthesis of silver, gold, zinc, and copper nanoparticles from those fungi has been getting good biological sources for significant reduction of mosquito larval and pupal populations. Fungal-based nanoparticles are highly effective and biorational insecticide for the control of vector populations. In this review, we discussed various sources of fungi that can be synthesized from different nanoparticles to control disease-transmitting mosquito vectors.

Antimicrobial Efficacy of Biogenic Silver and Zinc Nanocrystals/Nanoparticles to Combat the Drug Resistance in Human Pathogens

The emergence of biogenic nanomaterials as novel antimicrobials introduces a new paradigm in human health care. Based on the recent reports of the World Health Organization, infectious diseases pose one of the greatest health challenges. Increased multi-drug resistance prevalence among human pathogens, due to the inefficiency of commercially available antimicrobial drugs in the market is a great threat to humans. The poor solubility, stability and side effects of the antibacterial therapy prompted the researchers to explore new innovative strategies for developing new antimicrobials. Recently, biogenic nanoparticles have proven their effectiveness against multidrug-resistant (MDR) pathogens as an alternative to conventional antibiotics. Biogenic nanoparticles such as silver nanoparticles (AgNPs) and Zinc Oxide nanoparticles (ZnONPs) are easy to produce, biocompatible, provide enhanced uptake and are eco-friendly. Moreover, the capping of the biogenic nanocrystals provides an active surface for interaction with biological components, facilitated by free active surface functional groups to enhance their efficacy and delivery. Inorganic nanocrystals (AgNPs and ZnONPs) are effective both as nano-bactericides and as nanocarriers against sensitive and MDR) pathogens. The present chapter focuses on the utilization of the recent nanosystems to combat drug resistance in human pathogens. Nanomedicine represents a new generation of potiential antimicrobial candidates capable of combating the drug resistance in various pathogenic organisms.

Biogenic particles can be multiantigenic, immunostimulative and activate innate immunity while suppressing tumor development

Cancer immunotherapy, which attempts to activate or stimulate the immune system to treat cancer, has become the standard of treatment. Although some cancer vaccines are efficiently translated, they have not yet reached the same degree of success as infectious disease immunizations. A primary factor is the low immunogenicity of the tumor and related antigens. Unlike viruses, cancer cells emerge from somatic mutations in patients' healthy tissues, making it harder for the immune system to properly detect tumor cells. Biogenic nanoparticles have recently been highlighted as a solution to address some of the issues with creating anticancer vaccinations. Antigens, medication delivery, and others all benefit from biogenic nanoparticles. Biogenic nanoparticles have long been researched as a vaccine. Biogenic nanoparticles-based platforms, like particular VLPs, inherently activate inflammatory responses and may be increased with TAAs evaluated for antigen-specific antitumor responses to patient malignancies. OMVs and OMV-coated nanoparticles can be multiantigenic and immunostimulative in the box. PAMPs present in OMVs can activate innate immunity while suppressing tumor development. A range of cells, including immune and malignant cells, produce exosomes and play a critical role in cell-to-cell communication. Exosomes may contain interesting materials such as specific drugs, proteins, DNA, and RNA species, and their function depends on host cells. In cancer vaccines, however, these biogenic nanoparticles still have some limitations. Transferring tumor antigens and adjuvants to the secondary lymphoid system is a critical issue for biogenic nanoparticles. OMVs lack tumor antigens. Adjuvants are low in VLPs and exosomes. Furthermore, enhancing the protective response of biogenic nanoparticles, generating protective antigens in these nanoparticles and reducing the toxicity of nanoparticles are all challenges in cancer immunotherapy. There has been a lot of information regarding biogenic nanoparticles created by a variety of bacteria or cells in the area of bacterial vesicle research for a long time, but there has been a dearth of in-depth study focused on identifying molecules crucial to biogenesis or biogenic nanoparticles. Many basic questions remain unanswered here. Which envelope factors release biogenic nanoparticles? What signals and mechanisms regulate biogenic biogenic nanoparticles? Understanding these and other concepts as a cancer immunotherapy delivery technique is vital for the future development of biogenic nanoparticles. Future investigations are anticipated to begin to address these fundamental issues and increase our knowledge.

Biogenic Silver Nanoparticles as a Strategy in the Fight Against Multi-Resistant Salmonella enterica Isolated From Dairy Calves

Infectious diseases are one of the most important health problems worldwide, one of the main causes being the development of multi-resistant microorganisms. Likewise, the zoonotic potential of some pathogens and their ability to transfer resistance mechanisms, reduce the therapeutic options in both humans and animals. Salmonella enterica is an important pathogen that affects a wide range of animal species and humans, being Salmonella Typhimurium one of the most frequent serotypes affecting cattle, causing enteritis, diarrhea, and septicemia. The search for alternative therapeutic approaches has gained importance since the emergence of multidrug resistance to antibiotics and periodic outbreaks of salmonellosis. In this sense, the discovery of new drugs and the development of new strategies, such as the use of nanoparticles with antimicrobial activity, are very promising. The aim of this work was the extracellular production of biogenic silver nanoparticles using fungal extracts and the evaluation of their antimicrobial activity against resistant and multi-resistant Salmonella Typhimurium strains. We here demonstrated the potential of the biogenic nanoparticles as effective bacteriostatic and bactericidal agents for use in biomedical applications. In addition, Confocal Raman Microscopy and Atomic Force Microscopy were used to advance the understanding of the antimicrobial mechanism of biogenic nanoparticles against these pathogenic strains, the results of which suggested that the nanoparticles produced damage in several bacterial cell structures.

Biogenic Nanoparticles: Synthesis, Characterisation and Applications

Nanotechnology plays a big part in our modern daily lives, ranging from the biomedical sector to the energy sector. There are different physicochemical and biological methods to synthesise nanoparticles towards multiple applications. Biogenic production of nanoparticles through the utilisation of microorganisms provides great advantages over other techniques and is increasingly being explored. This review examines the process of the biogenic synthesis of nanoparticles mediated by microorganisms such as bacteria, fungi and algae, and their applications. Microorganisms offer a disparate environment for nanoparticle synthesis. Optimum production and minimum time to obtain the desired size and shape, to improve the stability of nanoparticles and to optimise specific microorganisms for specific applications are the challenges to address, however. Numerous applications of biogenic nanoparticles in medicine, environment, drug delivery and biochemical sensors are discussed.