Tailoring metal oxide nanozymes for biomedical applications: trends, limitations, and perceptions.

Nanomaterials with enzyme-like properties are known as 'nanozymes'. Nanozymes are preferred over natural enzymes due to their nanoscale characteristics and ease of tailoring of their physicochemical properties such as size, structure, composition, surface chemistry, crystal planes, oxygen vacancy, and surface valence state. Interestingly, nanozymes can be precisely controlled to improve their catalytic ability, stability, and specificity which is unattainable by natural enzymes. Therefore, tailor-made nanozymes are being favored over natural enzymes for a range of potential applications and better prospects. In this context, metal oxide nanoparticles with nanozyme-mimicking characteristics are exclusively being used in biomedical sectors and opening new avenues for future nanomedicine. Realising the importance of this emerging area, here, we discuss the mechanistic actions of metal oxide nanozymes along with their key characteristics which affect their enzymatic actions. Further, in this critical review, the recent progress towards the development of point-of-care (POC) diagnostic devices, cancer therapy, drug delivery, advanced antimicrobials/antibiofilm, dental caries, neurodegenerative diseases, and wound healing potential of metal oxide nanozymes is deliberated. The advantages of employing metal oxide nanozymes, their potential limitations in terms of nanotoxicity, and possible prospects for biomedical applications are also discussed with future recommendations.

Surface Engineered Peroxidase-Mimicking Gold Nanoparticles to Subside Cell Inflammation.

The smart design of nanoparticles with varying surfaces may open a new avenue for potential biomedical applications. Consequently, several approaches have been established for controlled synthesis to develop the unique physicochemical properties of nanoparticles. However, many of the synthesis and functionalization methods are chemical-based and might be toxic to limit the full potential of nanoparticles. Here, curcumin (a plant-derived material) based synthesis of gold (Au) nanoparticles, followed by the development of a suitable exterior corona using isoniazid (INH, antibiotic), tyrosine (Tyr, amino acid), and quercetin (Qrc, antioxidant), is reported. All these nanoparticles (Cur-Au, Cur-AuINH, Cur-AuTyr, and Cur-AuQrc) possess inherent peroxidase-mimicking natures depending on the surface corona of respective nanoparticles, and they are found to be excellent candidates for free radical scavenging action. The peroxidase-mimicking nanoparticle interactions with red blood cells and mouse macrophages confirmed their hemo- and biocompatible nature. Moreover, these surface-engineered Au nanoparticles were found to be suitable in subsiding key pro-inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß). The inherent peroxidase-mimicking behavior and anti-inflammatory potential without any significant toxicity of these nanoparticles may open new prospects for nanomedicine.

Engineered Nanomaterials for Immunomodulation: A Review.

The immune system usually provides a defense against invading pathogenic microorganisms and any other particulate contaminants. Nonetheless, it has been recently reported that nanomaterials can evade the immune system and modulate immunological responses due to their unique physicochemical characteristics. Consequently, nanomaterial-based activation of immune components, i.e., neutrophils, macrophages, and other effector cells, may induce inflammation and alter the immune response. Here, it is essential to distinguish the acute and chronic modulations triggered by nanomaterials to determine the possible risks to human health. Nanomaterials size, shape, composition, surface charge, and deformability are factors controlling their uptake by immune cells and the resulting immune responses. The exterior corona of molecules adsorbed over nanomaterials surfaces also influences their immunological effects. Here, we review current nanoengineering trends for targeted immunomodulation with an emphasis on the design, safety, and potential toxicity of nanomaterials. First, we describe the characteristics of engineered nanomaterials that trigger immune responses. Then, the biocompatibility and immunotoxicity of nanoengineered particles are debated, because these factors influence applications. Finally, future nanomaterial developments in terms of surface modifications, synergistic approaches, and biomimetics are discussed.

Double functionalized haemocompatible silver nanoparticles control cell inflammatory homeostasis.

Infection, trauma, and autoimmunity trigger tissue inflammation, often leading to pain and loss of function. Therefore, approaches to control inflammation based on nanotechnology principles are being developed in addition to available methods. The metal-based nanoparticles are particularly attractive due to the ease of synthesis, control over physicochemical properties, and facile surface modification with different types of molecules. Here, we report curcumin conjugated silver (Cur-Ag) nanoparticles synthesis, followed by their surface functionalization with isoniazid, tyrosine, and quercetin, leading to Cur-AgINH, Cur-AgTyr, and Cur-AgQrc nanoparticles, respectively. These nanoparticles possess radical scavenging capacity, haemocompatibility, and minimal cytotoxicity to macrophages. Furthermore, the nanoparticles inhibited the secretion of pro-inflammatory cytokines such as interleukin-6, tumor necrosis factor-α, and interleukin-1ß from macrophages stimulated by lipopolysaccharide (LPS). The findings reveal that the careful design of surface corona of nanoparticles could be critical to increasing their efficacy in biomedical applications.

Robotic-Assisted Hysterectomy for Benign Indications of Uteri Less Than Fourteen Weeks Size Versus More Than Fourteen Weeks Size: A Comparative Study.

Objectives This study was conducted to evaluate the feasibility of robotic hysterectomy for benign indications in patients with small size (<14 weeks) versus large size (>14 weeks) uterus. Methods This prospective study was conducted in a single centre from August 2018 to January 2020 in the Department of Obstetrics and Gynecology at All India Institute of Medical Sciences, Rishikesh (Uttarakhand). Surgical outcomes of 216 patients who underwent a robotic hysterectomy in our institution for benign indications were analysed. Women opting for definitive surgical management by minimally invasive technique were divided into two groups according to the size of the uterus less than 14 weeks (group 1) versus more than equal to 14 weeks (group 2). Data collected in both groups included intra-operative and post-operative parameters, length of hospital stay and morbidity if any. Results The demographic profile was comparable in both groups. The mean estimated blood loss was 180.78 ±68.0 ml (range, 10-340 ml) in group 1 and 253.49 ±57ml (range, 60-360 ml) in group 2 (p-value < 0.0001). However, the fall in haemoglobin level after 24 hours of surgery was not statistically significantly different between the two groups. The total duration of surgery in group 1 was 97.86 ± 12.0 minutes (range, 78-132 minutes) and in group 2 was 116.60 ± 15.4 minutes (range, 97-156 minutes), the difference being statically significant (p-value < 0.0001, 95% CI 103±2.1). Console time in group 1 was 43.84 ±6.0 minutes (range, 34-57 minutes) and in group 2 53.22 ±5.5 minutes (range, 44-66 minutes), the difference being statistically significant (p-value < 0.0001, 95% CI 46.57±0.97). There was no difference observed in terms of intra-operative and post-operative complications between the two groups. Conclusion The total duration of surgery and estimated blood loss were directly proportional to the size of the uterus. However, complication rate, hospital stay and requirement of post-op analgesia were comparable in both groups. Robotic surgery in a larger uterus is a feasible option in terms of better surgical outcomes and postoperative course. Thus, robotic hysterectomy in women with a large uterus is a suitable approach in the narrow region of the pelvis.