Novel nanomaterial-organism hybrids with biomedical potential

Instinctive hierarchically biomineralized structures of various organisms, such as eggs, algae, and magnetotactic bacteria, afford extra protection and distinct performance, which endow fragile organisms with a tenacious ability to adapt and survive. However, spontaneous formation of hybrid materials is difficult for most organisms in nature. Rapid development of chemistry and materials science successfully obtained the combinations of organisms with nanomaterials by biomimetic mineralization thus demonstrating the reproduction of the structures and functions and generation of novel functions that organisms do not possess.

The rational design of biomaterial-organism hybridization can control biological recognition, interactions, and metabolism of the organisms. Thus, nanomaterial-organism hybrids represent a next generation of organism engineering with great potential biomedical applications. This review summarizes recent advances in material-directed organism engineering and is mainly focused on biomimetic mineralization technologies and their outstanding biomedical applications. Three representative types of biomimetic mineralization are systematically introduced, including external mineralization, internal mineralization, and genetic engineering mineralization. The methods involving hybridization of nanomaterials and organisms based on biomimetic mineralization strategies are described. These strategies resulted in applications of various nanomaterial-organism hybrids with multiplex functions in cell engineering, cancer treatment, and vaccine improvement.

Unlike classical biological approaches, this material-based bioregulation is universal, effective, and inexpensive. In particular, instead of traditional medical solutions, the integration of nanomaterials and organisms may exploit novel strategies to solve current biomedical problems. This article is categorized under: Implantable Materials and

Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

Novel nanomaterial-organism hybrids with biomedical potential

Investigation on spectral and biomedical characterization of rhamnolipid from a marine associated bacterium Pseudomonas aeruginosa (DKB1)

Bio-surfactants are a principal group of significant molecules obtained from the microbial sources expressed with distinctive characteristics like biodegradation of hydrocarbons and also have different biomedical properties. The present investigation aims to assess the biomedical properties of synthesized bio-surfactant, rhamnolipid from Pseudomonas aeruginosa (DKB1) under in vitro conditions. The candidate bacterium P. aeruginosa (DKB1) was isolated from oil-polluted fishing harbors of Kanyakumari coast.

Initially, the bio-surfactant production by this candidate strain was confirmed by oil displacement assay, hemolytic assay, drop collapse assay and emulsification index. Further, the production of bio-surfactant was achieved through submerged fermentation process using Bushnell-Haas mineral salts medium supplemented with 2% olive oil. The yield of the bio-surfactant was attained as 2.4 g/l and confirmed as rhamnolipid through blue agar plate assay; further, the extracted rhamnolipid was purified and characterized through standard procedures. In stability studies, the rhamnolipid could withstand up to pH 12, temperature 100 °C and 15% of NaCl concentration. The biomedical application of rhamnolipid (30 μg ml^-1) was determined by antibacterial, antioxidant and cytotoxic studies. It exhibited a maximum growth inhibition against Bacillus subtilis (26 mm) with the MIC value of 8 μg ml^-1. In antioxidant test, rhamnolipid expressed significant (P < 0.0001) inhibition of total reducing power (44.11%), DPPH activity (61.60%), hydroxyl radical (83.30%) and nitric oxide (51.86%) scavenging ability at 100 μg ml^-1with the respective IC50 values of 130.50, 77.18, 52.08 and 95.43 μg ml^-1. The anticancer activity of the rhamnolipid was assessed with the help of MTT test against MCF-7, HT-29 and E-143 cancer cell lines individually, and the viability of the cells was observed, respectively, as 10.24, 17.66 and 13.50% at 250 μg ml^-1concentration with the respective IC50 values of 140.2, 81.02 and 138.9 μg ml^-1. From the results, it could be concluded that the rhamnolipid produced by P. aeruginosa (DKB1) isolated from oil-polluted area has effective biomedical properties.

Microbe Profile: Dictyostelium discoideum: model system for development, chemotaxis and biomedical research

The social amoeba Dictyostelium discoideum is a versatile organism that is unusual in alternating between single-celled and multi-celled forms. It possesses highly-developed systems for cell motility and chemotaxis, phagocytosis, and developmental pattern formation. As a soil amoeba growing on microorganisms, it is exposed to many potential pathogens; it thus provides fruitful ways of investigating host-pathogen interactions and is emerging as an influential model for biomedical research.

Assessment of transparency indicators across the biomedical literature: How open is open?

Recent concerns about the reproducibility of science have led to several calls for more open and transparent research practices and for the monitoring of potential improvements over time. However, with tens of thousands of new biomedical articles published per week, manually mapping and monitoring changes in transparency is unrealistic. We present an open-source, automated approach to identify 5 indicators of transparency (data sharing, code sharing, conflicts of interest disclosures, funding disclosures, and protocol registration) and apply it across the entire open access biomedical literature of 2.75 million articles on PubMed Central (PMC). Our results indicate remarkable improvements in some (e.g., conflict of interest [COI] disclosures and funding disclosures), but not other (e.g., protocol registration and code sharing) areas of transparency over time, and map transparency across fields of science, countries, journals, and publishers. This work has enabled the creation of a large, integrated, and openly available database to expedite further efforts to monitor, understand, and promote transparency and reproducibility in science.

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Cryoimmunology: Opportunities and challenges in biomedical science and practice

Autologous and allogeneic cryoimmunological medicine is a new branch of biomedical science and practice that examines the features and formation of the immune response to immunogenic properties of normal and malignant biological structures altered by ultralow temperature, as well as specific changes in the structural and functional characteristics of immune cells and tissues after cryopreservation. Cryogenic protein denaturation phenomenon provides important insights into the mechanisms underlying the damage to cryogenic lesions immediately after freeze-thawing sessions in bioscience and medicine applications. The newly formed cryocoagulated protein components (cryomodified protein components) are crucial in cryoimmunology from the perspective of the formation of immunological substances at ultralow temperatures. Dendritic cells and cryocell detritus (cryocell debris) formed in living biological tissue after exposure to ultralow temperature in vivo may be an indication of one of the essential mechanisms involved in the cryoimmunological response of living structures to the impact of ultralow temperature exposure. The formation of new autologous and allogeneic cryoinduced immunogenic substances is a novel concept in biomedical science. Accordingly, this review focuses on issues concerning the peculiarities of the interaction of the immune system with a dominant malignant neoplasm tissue after exposure to subzero temperatures, considering the original cryogenic technical approaches. We present an overview of the state-of-the-art methods of cryoimmunology, and their major developments, past and present. The need for the delineation of structural and functional c