Antimicrobial peptide mimetic minimalistic approach leads to very short peptide amphiphiles-gold nanostructures for potent antibacterial activity.

Strategically controlling concentrations of lipid-conjugated L-tryptophan (vsPA) guides the self-assembly of nanostructures, transitioning from nanorods to fibres and culminating in spherical shapes. The resulting Peptide-Au hybrids, exhibiting size-controlled 1D, 2D, and 3D nanostructures, show potential in antibacterial applications. Their high biocompatibility, favourable surface area-to-volume ratio, and plasmonic properties contribute to their effectiveness against clinically relevant bacteria. This controlled approach not only yields diverse nanostructures but also holds promise for applications in antibacterial therapeutics.

Silver-Nanoparticle-Embedded Short Amphiphilic Peptide Nanostructures and Their Plausible Application to Reduce Bacterial Infections.

The microbiota-gut-brain axis (GBA) plays a critical role in the development of neurodegenerative diseases. Dysbiosis of the intestinal microbiome causes a significant alteration in the gut microbiota of Alzheimer's disease (AD) patients, followed by neuroinflammatory processes. Thus, AD beginning in the gut is closely related to an imbalance in gut microbiota, and hence a multidomain approach to reduce this imbalance by exerting positive effects on the gut microbiota is needed. In one example, a tyrosine-based short peptide amphiphile (sPA) was used to synthesize antibacterial AgNPs-sPA nanostructures. Such nanostructures showed high biocompatibility and low cytotoxicity, and therefore work as model drug delivery agents for addressing local bacterial infections. These may have therapeutic value for the treatment of microbiota-triggered progression of neurodegenerative diseases.

Short peptide amphiphile nanostructures facilitate sunlight-induced nanowelding of gold nanosheets.

An effortless thermoplasmonic welding of multi-shaped gold nanosheets is achieved by ordinary and simple sunlight irradiation. A light-matter interaction occurred via the nanogaps of smaller nanosheets, leading to the enhancement of the electromagnetic field and thus effectively concentrating the heat at the welding point. The sPA peptide nanostructure facilitates the nanowelding of small caged gold nanostructures.

Mercury-instructed assembly (MiA): architecting clathrin triskelion-inspired highly functional C3-symmetric triskelion nanotorus functional structures into microtorus structures.

To detect heavy metal toxicity using self-assembled nanostructures, a clathrin triskelion-inspired highly functional C3-symmetric trimerized biotinylated di-tryptophan peptide was used. This triskelion peptide is known to self-assemble into nanotorus-like structures and can therefore act as a nanocage for various analytes. In this work, in addition to spectroscopy, force and electron microscopy were successfully used to detect the effect of toxic metal ions such as zinc, cadmium, and mercury by exploiting the change in the nanotorus morphology. Different concentrations of mercury led to the expansion of nanotorus structures into microtori. Therefore, we provide a unique application of heavy metal toxicity by utilizing "material nanoarchitectonics" to architect nanotorus structures into higher-order microtorus structures, as instructed by mercury. Such a strategy can make heavy metal sensing easier for materials scientists and open new avenues for biomedical/environmental science applications.

Amyloid-ß Inspired Short Peptide Amphiphile Facilitates Synthesis of Silver Nanoparticles as Potential Antibacterial Agents.

An amyloid-ß inspired biocompatible short peptide amphiphile (sPA) molecule was used for controlled and targeted delivery of bioactive silver nanoparticles via transforming sPA nanostructures. Such sPA-AgNPs hybrid structures can be further used to develop antibacterial materials to combat emerging bacterial resistance. Due to the excellent antibacterial activity of silver, the growth of clinically relevant bacteria was inhibited in the presence of AgNPs-sPA hybrids. Bacterial tests demonstrated that the high biocompatibility and low cytotoxicity of the designed sPA allow it to work as a model drug delivery agent. It therefore shows great potential in locally addressing bacterial infections. The results of our study suggest that these nanodevices have the potential to trap and then engage in the facile delivery of their chemical payload at the target site, thereby working as potential delivery materials. This system has potential therapeutic value for the treatment of microbiota triggered progression of neurodegenerative diseases.

Microalgal drugs: A promising therapeutic reserve for the future.

Over the decades, a variety of chemically synthesized drugs are being used to cure existing diseases but often these drugs could not be effectively employed for the treatment of serious and newly emerging diseases. Fortunately, in nature there occurs immense treasure of plants and microorganisms which are living jewels with respect to their richness of medically important metabolites of high value. Hence, amongst the existing microorganism(s), the marine world offers a plethora of biological entities that can contribute to alleviate numerous human ailments. Algae are one such photosynthetic microorganism found in both marine as well as fresh water which are rich source of metabolites known for their nutrient content and health benefits. Various algal species like Haematococcus, Diatoms, Griffithsia, Chlorella, Spirulina, Ulva, etc. have been identified and isolated to produce biologically active and pharmaceutically important high value compounds like astaxanthin, fucoxanthin, sulphur polysaccharides mainly galactose, rhamnose, xylose, fucose etc., which show antimicrobial, antifungal, anti-cancer, and antiviral activities. However, the production of either of these bio compounds is favored under conditions of stress. This review gives detailed information on various nutraceutical metabolites extracted from algae. Additionally focus has been made on the role of these bio compounds extracted from algae especially sulphur polysaccharides to treat several diseases with prospective treatment for SARS-CoV-2. Lastly it covers the knowledge gaps and future perspectives in this area of research.