Advanced flexible transvaginal mesh with high visibility under computerized tomography (CT) scan.

Pelvic floor disorders, including pelvic organ prolapse (POP) and stress urinary incontinence (SUI), are serious and very common. Surgery is commonly undertaken to restore the strength of the vaginal wall using transvaginal surgical mesh (TVM). However, up to 15% of TVM implants result in long-term complications, including pain, recurrent symptoms, and infection.Clinical Relevance- In this study, a new bioengineered TVM has been developed to address these issues. The TVM is visible using noninvasive imaging techniques such as computed tomography (CT); it has a highly similar structural profile to human tissue and potential to reduce pain and inflammation. These combined technological advances have the potential to revolutionize women's health.

Investigation of Antimicrobial Activity and Biocompatibility of Biogenic Silver Nanoparticles Synthesized using Syzigyum cymosum Extract.

Nanotherapeutics has emerged as the most sought after approach to tackle the menace of drug-resistant pathogenic bacteria. Among others, biogenic silver nanoparticles (bAgNPs) synthesized using medicinal plant extracts demonstrate promising antibacterial propensity with excellent biocompatibility. Herein, bAgNPs were synthesized through the green chemistry approach using Syzygium cymosum leaf extract as a reducing agent at different pH values (i.e., 5, 7, 8, and 10). The average size of bAgNPs synthesized at pH 5, 7, 8, and 10 was 23.3, 21.3, 17.2, and 35.3 nm, respectively, and all the nanoparticles were negatively charged. Their antibacterial potential was investigated against Bacillus subtilis, Escherichia coli DH5α, E. coli K12, enteropathogenic E. coli, and Salmonella typhi. The highest antibacterial activity was exhibited by bAgNPs synthesized at pH 8 against all the tested bacterial strains, which can be attributed to their small size and greater surface area to volume ratio. The bAgNPs demonstrated the highest zone of inhibition (29.5 ± 0.8 mm) against B. subtilis through oxidation of membrane fatty acids that resulted in the formation of the malondialdehyde-thiobarbituric acid (MDA-TBA) adduct. However, bAgNPs demonstrated excellent hemocompatibility with rat and human red blood cells. Biogenic AgNPs synthesized at pH 8 also exhibited biocompatibility in terms of liver and kidney function biomarkers. Furthermore, hematoxylin and eosin staining of the tissue sections of vital organs (i.e., liver, kidneys, lungs, heart, spleen, and brain) also confirmed the biocompatibility of bAgNPs.

Functionalized Concave Cube Gold Nanoparticles as Potent Antimicrobial Agents against Pathogenic Bacteria.

Gold (Au) is an inert metal in a bulk state; however, it can be used for the preparation of Au nanoparticles (i.e., AuNPs) for multidimensional applications in the field of nanomedicine and nanobiotechnology. Herein, monodisperse concave cube AuNPs (CCAuNPs) were synthesized and functionalized with a natural antioxidant lipoic acid (LA) and a tripeptide glutathione (GSH) because different crystal facets of AuNPs provide binding sites for distinct ligands. There was an ∼10 nm bathochromic shift of the UV-vis spectrum when CCAuNPs were functionalized with LA, and the size of the as-synthesized monodisperse CCAu nanoparticles was 76 nm. The LA-functionalized CCAu nanoparticles (i.e., CCAuLA) showed the highest antibacterial activity against Bacillus subtilis. Both fluorescence images and scanning electron microscopy images confirm the damage of the bacterial cell wall as the mode of antibacterial activity of CCAuNPs. CCAuNPs also cause the oxidation of bacterial cell membrane fatty acids to produce reactive oxygen species, which pave the way for the death of bacteria. Both CCAu nanoparticles and their functionalized derivatives showed excellent hemocompatibility (i.e., percentage of hemolysis is <5% at 80 µg of AuNPs) to human red blood cells and very high biocompatibility to HeLa, L929, and Chinese hamster ovary-green fluorescent protein (CHO-GFP) cells. Taken together, LA and GSH enhance the antibacterial activity and biocompatibility, respectively, of CCAu nanoparticles that interact with the bacteria through Coulomb as well as hydrophobic interactions before demonstrating antibacterial propensity.

Nanodiamond-chitosan functionalized hernia mesh for biocompatibility and antimicrobial activity.

Polypropylene (PP) mesh is most commonly used for the treatment of hernia and pelvic floor construction. However, some of the patients have a few complications after surgery due to the rejection or infection of the implanted meshes. The poor biocompatibility of PP mesh, low wettability results in poor cell attachment/proliferation and restricts the loading of antibacterial agent, leading to a slow healing process and high risk of infection after surgery. Here in this study, a new technique has been employed to develop a novel antimicrobial and biocompatible PP mesh modified with bioactive chitosan and functionalized nanodiamond (FND) for infection inhibition and acceleration of the healing process. An oxygen plasma treatment PP mesh was used then chitosan was strongly attached to the surface of the PP fibers. Subsequently, FND as an antibacterial agent was loaded into the chitosan modified PP fiber to provide desired antibacterial functions. The meshes were characterised with XRD, FTIR, SEM, EDX, water contact angle, confocal, and optical microscopy. The modified PP mesh with chitosan and FND showed a significant increase in its hydrophilicity and L929 fibroblast cell attachment. Furthermore, the modified mesh exhibited great antibacterial efficiency against Escherichia coli. Therefore, the newly developed technique to modify PP mesh could be a promising technique to generate a biocompatible PP mesh to accelerate the healing process and reduce the risk of infection after surgery.

Polypropylene-nanodiamond composite for hernia mesh.

Commercial hernia mesh is commonly made from polypropylene (PP), due to its inertness, biocompatibility, physical properties, ease of processing and versatility for conversion into flexible shape. However, reportedly hernia mesh prepared from PP experienced issues such as diminished long-term strength, foreign body rejection, lack of biocompatibility and high adhesion to the abdomen wall. Infiltration of the mesh by soft tissue (called remodeling) results in an integration of mesh into the body, leading to a rapid reduction in mesh mechanical properties and potential infection. Here, this study addresses these issues through the incorporation of nanodiamond (ND) into PP filament and coating on the surface of plasma-treated PP-ND mesh. The results show that the dynamic modulus of the PP-ND mesh increased significantly, without compromising its flexibility. Coating PP-ND mesh with hydroxylated ND led to a reduction in nonspecific protein adsorption onto the surface of nanocomposite, which is an important characteristic for hernia mesh to prevent foreign body reaction, attachment of mesh to the abdominal wall and nearby organs. In-vitro study with mammalian cells shows that coated PP-ND mesh with functionalized ND exhibits a significant increase in the number of adhered cells with more elongated morphology in comparison with other PP meshes, due to the better hydrophilicity. Therefore, the ND coated nanocomposite mesh can be a promising candidate for hernia repair in the future; however, more investigation is required.

Three-dimensional directional nerve guide conduits fabricated by dopamine-functionalized conductive carbon nanofibre-based nanocomposite ink printing.

A potential issue in current nerve guides is that they do not transmit electrical nerve impulses between the distal and proximal end of an injured nerve, i.e. a synapse. Conductivity is a desirable property of an ideal nerve guide that is being considered for peripheral nerve regeneration. Most conductive polymers reported for the fabrication of tissue engineering scaffolds, such as polypyrrole and polyaniline, are non-biodegradable and possess weak mechanical properties, and thus cannot be fabricated into 3D structures. Herein, we have designed a new nanocomposite material composed of dopamine, carbon nanofibers (CNF) and polycaprolactone (PCL) for the fabrication of nerve conduits, which facilitates the growth and migration of neurons toward the targeted end of an injured nerve. This support and navigation of the scaffold leads to better sensory and motor function. The results showed that the mechanical properties of the printed PCL increased by 30% in comparison with the pure PCL film, which is comparable with human nerves. The in vitro cell study of human glioma cells showed that the printed lines provided support for neural cell attachment, migration and differentiation toward the targeted end. In contrast, in the absence of printed lines in the scaffold, the cells attach and grow in random directions, forming a flower shape (cell cluster) on the surface of PCL. Thus, the proposed scaffold is a promising candidate for nerve guide application based on its signal transmission and navigating neurons in a correct pathway towards the targeted end.

Correction: Three-dimensional directional nerve guide conduits fabricated by dopamine-functionalized conductive carbon nanofibre-based nanocomposite ink printing.

[This corrects the article DOI: 10.1039/D0RA06556K.].

Synthesis of Biogenic Silver Nanoparticles Using Caesalpinia digyna and Investigation of Their Antimicrobial Activity and In Vivo Biocompatibility.

Among metallic nanoparticles, silver nanoparticles (AgNPs) have a wide spectrum of medical applications. Herein, biogenic silver nanoparticles (bAgNPs) were prepared from extracts of Caesalpinia digyna leaf as a reducing agent at different pH values (i.e., 5, 7, 8, and 10). The as-synthesized bAgNPs were characterized using UV-vis and Fourier transform infrared (FTIR) spectroscopies, scanning transmission electron microscopy, powder X-ray diffraction analysis, dynamic light scattering, and ζ-potential analysis. The sizes of bAgNPs prepared at pH 5, 7, 8, and 10 were 45.4, 11.3, 11.4, and 40.8 nm, respectively, and all of the nanoparticles were negatively charged. The antimicrobial activity of the as-prepared bAgNPs was investigated against Bacillus subtilis, Escherichia coli DH5α, E. coli K12, enteropathogenic E. coli (EPEC), and Salmonella typhi. The bAgNPs prepared at pH 8 showed the highest antibacterial propensity against all of the bacterial strains as exhibited in the zone of inhibition (ZOI) as well as the CellTox green assay, which can be due to their relatively small size, stability, and higher surface area-to-volume ratio. The bAgNPs synthesized at pH 8 showed the highest ZOI against B. subtilis, which was ∼25 mm in diameter. The lipid peroxidation assay demonstrated the formation of the malondialdehyde-thiobarbituric acid (MDA-TBA) adduct while treating the bacteria with bAgNPs due to the oxidation of fatty acids present in the membrane. The highest amount of MDA-TBA adduct was observed when Gram-positive B. subtilis was exposed to bAgNPs. On the contrary, rats treated with bAgNPs demonstrated no significant toxicity in terms of hematological and biochemical parameters. The bAgNPs also showed excellent compatibility with human red blood cells. Overall, bAgNPs synthesized at pH 8 have superior antimicrobial activity and excellent biocompatibility and, therefore, can be used as potential antibacterial agents.

Investigation of the Antibacterial Activity and in vivo Cytotoxicity of Biogenic Silver Nanoparticles as Potent Therapeutics.

Biogenic nanoparticles are the smartest weapons to deal with the multidrug-resistant "superbugs" because of their broad-spectrum antibacterial propensity as well as excellent biocompatibility. The aqueous biogenic silver nanoparticles (Aq-bAgNPs) and ethanolic biogenic silver nanoparticles (Et-bAgNPs) were synthesized using aqueous and ethanolic extracts of Andrographis paniculata stem, respectively, as reducing agents. Electron microscopic images confirmed the synthesis of almost spherical shaped biogenic silver nanoparticles (bAgNPs). The zeta potentials of the nanoparticles were negative and were -22 and -26 mV for Aq-bAgNPs and Et-bAgNPs, respectively. The antibacterial activity of bAgNPs was investigated against seven pathogenic (i.e., enteropathogenic Escherichia coli, Salmonella typhi, Staphylococcus aureus, Vibrio cholerae, Enterococcus faecalis, Hafnia alvei, Acinetobacter baumannii) and three nonpathogenic (i.e., E. coli DH5α, E. coli K12, and Bacillus subtilis) bacteria at different time points (i.e., 12, 16, 20, and 24 h) in a dose-dependent manner (i.e., 20, 40, and 60 µg) through broth dilution assay, disk diffusion assay, CellToxTM Green uptake assay, and trypan blue dye exclusion assay. The lowest minimum inhibitory concentration value for both the bAgNPs was 0.125 µg. Et-bAgNPs showed the highest antibacterial activity against S. aureus at 60 µg after 16 h and the diameter of inhibited zone was 28 mm. Lipid peroxidation assay using all the bacterial strains revealed the formation of malondialdehyde-thiobarbituric acid adduct due to the oxidation of cell membrane fatty acids by bAgNPs. The bAgNPs showed excellent hemocompatibility against human as well as rat red blood cells. Furthermore, there was no significant toxicity observed when the levels of rat serum ALT, AST, γ-GT (i.e., liver function biomarkers), and creatinine (i.e., kidney function biomarker) were determined.

Surface-Functionalized Polypropylene Surgical Mesh for Enhanced Performance and Biocompatibility.

Polypropylene (PP) surgical mesh has attracted vast attention due to its chemical inertness and excellent mechanical properties. However, improvement is necessary to enhance its biocompatibility and to prevent unwanted tissue adhesion. This study addresses these issues through surface modification of plasma-activated PP mesh with a 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer. Reaction time and monomer concentration have been optimized to achieve the optimal biocompatibility with reduction in protein adsorption. Attenuated total reflection-Fourier transform infrared spectra confirmed the grafting of the MPC polymer (PMPC) to the plasma-activated polypropylene (PPP) mesh. Scanning electron microscopy images and energy-dispersive X-ray (EDX) line spectra exhibited morphological changes and specifically PMPC grafting to the surface of PPP mesh, due to the presence of a significant amount of phosphorus (P) on the grafted PPP mesh. PMPC-grafted polypropylene (PPP-PMPC) showed a significant reduction in contact angle as well as the amount of adsorbed bovine serum albumin (BSA) protein in comparison with pristine PP mesh. The highest reduction in protein adsorption and the lowest contact angle were achieved at the monomer concentration of 0.3 M and the reaction time of 90 min. A longer reaction time and higher monomer concentration resulted in clogging within the mesh pores. MTT assay results (∼90% cell viability) confirmed the nontoxicity of the PMPC-grafted mesh, while optical microscopic and SEM images showed increased resistance of cell attachment to the surface of PMPC-grafted mesh. The results show that PPP-PMPC can be a promising biomaterial to address the current issues in biocompatibility and reduction in adhesion after surgery.