Sachin Kumar

One-pot hydrothermal green synthesis of polymer nanoglue from soy-protein isolate for accelerated wound healing through light-activated redox regulation.

Globally, millions of individuals suffer from facial defects due to congenital anomalies, or trauma. Maxillofacial prosthetics use tissue‐like synthetic materials to restore facial form and function. However, performance of these materials is highly influenced by climate conditions, creating a critical need for prosthesis materials tailored to specific environmental conditions. In this study, we developed soft room‐temperature vulcanizing (RTV) silicone based elastomeric materials for maxillofacial prosthetic applications, with particular emphasize on suitability for the Indian climate. Prosthetic materials were prepared at room temperature using a unidirectional vacuum mixing process at −890 mbar, with mixing speed 300–400 rpm and mixing time 10 min. A systematic formulation strategy based on design of experiments (DOE) was employed, wherein the weight ratio of crosslinker to base elastomer, silica filler and UV absorber were systematically varied. Initially, 25 formulations were developed according to the DOE, and preliminary evaluated for tensile strength, tear strength and hardness. Based on these results 5 optimized formulations were selected for detailed analysis of structural characteristics, thermal stability, filler‐induced microstructures, water sorption behavior, surface hydrophobicity, mechanical properties and cytocompatibility. The optimized RTV specimens exhibited tear strength of ~11.7–14.6 N/mm, tensile strength of ~2.8–5.5 MPa, Shore A hardness below 40, surface hydrophobicity with contact angle ~100°, very low water sorption (~0.1%–0.3% up to 240 h) and excellent cytocompatibility. In vitro cytocompatibility studies revealed high cell viability, suggesting that the developed RTV specimens effectively support cell survival and exhibit excellent cytocompatibility. To evaluate the suitability for the Indian climate, specimens were subjected to 3 and 6 months of natural weathering. After 6 months, the developed RTV formulations showed ~10%–15% increase in tensile strength, tear strength and Shore A hardness, whereas, the control formulation (without UV stabilizer and other additives), showed ~25%–30%, increase along with noticeable color change. These findings demonstrate the improved weathering stability of the developed formulations under Indian climate conditions. Finally, a prosthetic ear was successfully fabricated using an in‐house customized mould which demonstrates the practical applicability and suitability of the developed formulation.

The inertness of poly(ɛ-caprolactone) scaffolds was overcome using hydroxyethyl cellulose as a macroinitiator to introduce functional sites for type I collagen immobilization, enhancing their bioactivity and suitability for biomedical applications.

Protein interactions on graphene-based materials (GBMs) are predominantly governed by interphase surface properties such as surface chemistry and roughness; however, the critical role of surface potential (SP) in modulating these interactions remains largely unexplored. In this work, we investigated a model study highlighting how two distinct GBMs [graphene oxide (GO) and reduced graphene oxide (RGO)] with different SP regulate protein interactions, spanning from macroscopic adsorption to molecular-level conformational changes. Through thermal reduction, hydrophilic GO was transformed into hydrophobic RGO, generating distinct SP of +120 mV for GO and +60 mV for RGO. This modulation in SP created a platform for differential protein interactions. The influence of SP on protein interactions was evident when fibronectin (FN) was introduced onto GO and RGO surfaces. Quartz crystal microbalance with dissipation and fluorescence microscopy revealed that the distinct SP of GO and RGO surfaces significantly affected FN adsorption. On the RGO substrate, which exhibited a lower SP, FN adsorption was ∼3 times greater than on the GO substrate. In contrast, FN on the GO adopted elongated fibrillar structures, driven by strong polar, hydrophilic, and electrostatic interactions at the molecular scale, regulating its conformation upon adsorption. Molecular docking simulations further supported these findings, indicating a stronger and more stable interaction between FN and RGO (binding energy C-score: −3.87, RMSD: 0.01 Å) than between FN and GO (C-score: −2.24, RMSD: 0.42 Å). Overall, this study underscores the pivotal role of SP of GBMs in modulating protein adsorption, binding stability, and conformational organization, providing key insights into the rational design of GBM biomaterials with tailored biointerface properties.

Advancements in tissue engineering and regenerative medicine have highlighted different strategies of engineering and designing hydrogels to replicate the intricate structure of cartilage extracellular matrix (ECM) for effective cartilage regeneration. However, despite efforts to meet the elevated structural and mechanical demands of cartilage repair, researchers often overlook the challenging environmental conditions at damaged cartilage sites such as inflammation, hypoxia, and the limited availability of nutrients and energy, which are critical for supporting tissue regeneration. The insufficient oxygen, nutrient availability, and oxidative stress in avascular cartilage limit the oxidative phosphorylation-mediated bioenergetics in cells needed for energy demands required for anabolic biosynthesis, cell division, and migration during tissue repair. Thus, there is a need to develop an advanced approach to engineer a unique hydrogel system that not only provides intricate structural properties but also integrates therapeutics (like anti-inflammatory, reactive oxygen species (ROS) scavenging) and bioenergetics (like oxygen, energy demand) into the hydrogel, which may offer a holistic and effective solution for repairing cartilage defects under a harsh microenvironment. In this study, we engineered an innovative approach to develop a new class of theraoenergetic hydrogel system by reinforcing a Janus nanofiber (JNF) carrying therapeutic (MgO) and bioenergetic (polyglutamic acid), PGA) components into a dual network photo-crosslinkable hydrogel. Reinforcement of JNF microfragments and the photo-crosslinking dual network of synthesized gelatin methacryloyl (GelMA) and carboxymethyl chitosan (CMCh) not only enhances the hydrogel's mechanical properties by 800% to withstand mechanical load but also ensures a controlled release of magnesium, oxygen, and PGA over 30 days. Co-delivery of magnesium and bioenergetic PGA with oxygen helped synergistically to reduce intracellular ROS and inflammatory markers IL-6 and TNF-α, providing a supportive environment for enhancing cell mitochondrial oxidative metabolism leading to active proliferation and chondrogenic differentiation of stem cells to deposit glycosaminoglycan (GAG)-rich extracellular matrix to regenerate cartilage. The developed theraoenergetic hydrogel system represents a promising solution for regenerating cartilage under a harsh microenvironment to treat osteoarthritis, a rising global health burden.

In the pursuit of new wound care products, researchers are exploring methods to improve wound healing through exogenous wound healing products. However, diverging from this conventional approach, this work has developed an endogenous support system for wound healing, drawing inspiration from the body's innate healing mechanisms governed by the sequential release of metal ions by body at wound site to promote different stages of wound healing. This work engineers a multi‐ion‐releasing sprayable hydrogel system, to mimic this intricate process, representing the next evolutionary step in wound care products. It comprises Alginate (Alg) and Fibrin (Fib) hydrogel infused with Polylactic acid (PLA) polymeric microcarriers encapsulating multi (calcium, copper, and zinc) nanoparticles (Alg‐Fib‐PLA‐nCMB). Developed sprayable Alg‐Fib‐PLA‐nCMB hydrogel show sustained release of beneficial multi metallic ions at wound site, offering a range of advantages including enhanced cellular function, antibacterial properties, and promotion of crucial wound healing processes like cell migration, ROS mitigation, macrophage polarization, collagen deposition, and vascular regeneration. In a comparative study with a commercial product (Midstress spray), developed Alg‐Fib‐PLA‐nCMB hydrogel demonstrates superior wound healing outcomes in a rat model, indicating its potential for next generation wound care product, addressing critical challenges and offering a promising avenue for future advancements in the wound management.