Fabrication of silk fibroin film enhanced by acid hydrolyzed silk fibroin nanowhiskers to improve bacterial inhibition and biocompatibility efficacy

In this study, silk fibroin nanowhiskers (SNWs) were extracted from natural silk fiber by sulfuric acid hydrolysis with the assistance of ultrasonic wave treatment. The obtained SNWs were mixed with regenerated silk fibroin (RSF) solution to fabricate the SNWs/RSF films. The fabricating SNWs were systematically characterized by using SEM, FTIR, and the SNWs/RSF films were observed by digital camera, PM, etc. The results show that the monodisperse SNWs are evenly distributed in the RSF film. The presence of SNWs in RSF film significantly improves the performances of the film, including the swelling ability, mechanical properties, hydrophilicity, antibacterial efficacy, cytocompatibility. Meanwhile, the SNWs/RSF film can endorse the wound healing efficiency in vivo mice wound site. The proposed techniques for extracting SNWs and fabricating silk fibroin composite film may provide a valuable method for creating an ideal silk-based material for biomedical applications.

Fabrication of heteroatom doped NFP-MWCNT and NFB-MWCNT nanocomposite from imidazolium ionic liquid functionalized MWCNT for antibiofilm and wound healing in Wistar rats: Synthesis, characterization, in-vitro and in-vivo studies

Bacterial biofilm is an obstacle for wound healing because it can affect the epithelialization, development of granular cells, and other regular inflammatory procedures. It plays the role of safeguarding pathogens from antiseptics and antibiotics. In this respect, this research work aims to develop heteroatom (N, F, P/B) incorporated multi-walled carbon nanotubes (MWCNT), such as NFP-MWCNT and NFB-MWCNT, which can maximize the wound healing efficacy via destroying the wound pathogen and biofilms. NFP-MWCNT and NFB-MWCNT were obtained using self-assembling ionic liquids (ILs) such as BMIM-PF₆ and BMIM-BF₄ in an acid-functionalized MWCNT (A-MWCNT) suspension, followed by pyrolysis in a nitrogen atmosphere. The composite formation was established by FTIR, XRD, RAMAN, EDX mapping, and XPS spectroscopy. TEM and SEM analyses confirmed the bamboo stick-like morphology. During this reaction, IL molecules might be cross-linked with A-MWCNT via hydrogen bonding and ionic interaction, with further pyrolysis producing the defects with doping of N, F, P, or B elements. Finally, they were assessed for their antibiofilm activity against typical bacterial strains such as K. pneumoniae, P. aeruginosa, E. coli (Gram-negative), and B. subtilis (Gram-positive), using a quantitative estimation approach. The results revealed greater effectiveness of NFB-MWCNT and NFP-MWCNT, compared to pristine MWCNT. The antibiofilm activity of NFP-MWCNT and NFB-MWCNT was associated with their specific surface chemistry (due to the presence of N, F, P/B heteroatoms), and their nanosize. Moreover, the synthesized material was examined for its wound-healing ability in Wistar rats. The results proved that cells cultured on NFB-MWCNT and NFP-MWCNT displayed exceptional healing ability. The different electronegativity between the heteroatoms creates the surface charge that inhibits the biofilm formation, leading to healing the wounds together with the heteroatom mineral source for mouse fibroblast regeneration and granulation. This is the first study in which the role of different heteroatoms incorporated into MWCNT is examined in the context of antibiofilm-associated wound-healing ability.

A dopamine-functionalized aqueous-based silk protein hydrogel bioadhesive for biomedical wound closure

The functionalization of a PEGylated silk protein hydrogel with dopamine significantly improved its wet adhesive strength.

Ionic liquid - A greener templating agent with Justicia adhatoda plant extract assisted green synthesis of morphologically improved Ag-Au/ZnO nanostructure and it's antibacterial and anticancer activities

Metal and metal oxide nanoparticles (NPs) possess significant properties that are promising materials for biological applications. In this research work, we prepared ionic liquid assisted Ag-Au/ZnO NPs, using J.adhatoda leaves extract by hydrothermal method. Ionic liquids performed as a stabilizing and templating agent to improve the surface morphology of the synthesized Ag and Au doped ZnO NPs. The prepared ZnO, Ag-doped ZnO, Au doped ZnO, and AgAu doped ZnO NPs exhibit the average crystalline size of 36, 34, 32, and 25 nm and their band gap energy values are 3.36, 3.29, 3.17, and 2.98 eV respectively. The XRD and UV-DRS result shows that after doping of Au and Ag the ZnO crystalline size and band gap energy was decreased, which leads to enhanced the biomedical (antibacterial and anticancer) properties of AgAu doped ZnO NPs. The Raman active mode of A₁ (LO) and A₁ (TO) showed that the formation of lattice defects due to the Ag and Au doping in the ZnO crystalline plane to improve the Ag-Au/ZnO properties. SEM and TEM images revealed that the prepared AgAu doped ZnO NPs exhibits nano stick shape with particle size range from 20 to 25 nm. The EDX spectrum and elemental mapping results confirmed that Ag and Au atoms are doped and spread over the ZnO NPs. The corresponding SAED pattern also confirms the crystallinity of Ag-Au/ZnO NPs. Furthermore, the synthesized Ag-Au/ZnO NPs has been explored for its antibacterial and anticancer activities. It shows good antibacterial activity against E.coli and S.aureus bacteria. Additionally, the Ag-Au/ZnO NPs show excellent anticancer activity against the HeLa cancer cells. The excellent antibacterial and anticancer results prove that the bi-metal (Ag and Au) doping can enhance the biomedical properties of ZnO NPs. It will be a promising material in the biomedical field.

Ornamental morphology of ionic liquid functionalized ternary doped N, P, F and N, B, F-reduced graphene oxide and their prevention activities of bacterial biofilm-associated with orthopedic implantation

The multifunctional biological active material design for bone tissue engineering is essential to induce osteoblast cell proliferation and attachment. Adhesion of bacteria on biomaterials to produce biofilms can be major contributors to the pathogenesis of implant material associated infections. This research work focuses on NPF& NBF elemental doping and functionalization of reduced graphene oxide using an imidazolium-based ionic liquid such as BMIM PF₆ and BMIM BF₄ by hydrothermal method. The resulting tri doped reduced graphene oxide (NPF-rGO and NBF-rGO) composite was further used as a scaffold for bone tissue engineering and anti-biofilm activities. The observation of the effect of NPF-rGO and NBF-rGO on the morphology, adhesion and cell proliferation of HOS cell was investigated. Moreover, the tri doped composite tested its antibiofilm properties against B. subtilis, E. coli, K. pneumoniae, and P. aeruginosa pathogenic bacteria. In-vitro studies clearly show the effectiveness of N, P, B, and F doping promoting the rGO mineralization, biocompatibility, and destruction of bacterial biofilm formation. The result of this study suggests that NPF-rGO and NBF-rGO hybrid material will be a promising scaffold for bone reaeration and implantation with a minimal bacterial infection.

Influences of ionic liquid and temperature on the tailorable surface morphology of F-apatite nanocomposites for enhancing biological abilities for orthopedic implantation

This report has approached for the green synthesis of morphological controlled novel metal-doped fluorinated apatite/polymeric nanocomposites. The synthesized nanocomposites have investigated for hard tissue engineering and bone substitute applications. The selected fluoro ionic liquid explored the dual performances as fluorine precursor and as a soft template for the morphological development of apatite nanocomposite synthesis. The structural and surface studies (XRD, FTIR, FE-SEM, EDS, AFM, HR-TEM & SAED) confirmed the crystalline and morphological changes of synthesized fluorohydroxyapatite nanostructures at two different reaction temperatures. The fluorinated apatite nanocomposites doped with silver for metal-doped composites, which have effective antibacterial efficacy and favorable biocompatibility. The silver-doped nanocomposites showed excellent antibacterial ability against Staphylococcus aureus and Escherichia coli bacterial pathogens with the uniform release of silver and fluorine ions. These antibacterial performances have systematically tested by the quantitative and qualitative methods. The rod-like fluorinated apatite nanocrystals promote cell adhesion and viability of human osteosarcoma (MG-63) cell lines and these studies compared with the sheet-like apatite nanocomposites. This type of biomedical apatite materials may be a promising material for orthopedic implant and regeneration applications.