Giriprasath Ramanathan

Fabrication and characterization of a collagen coated electrospun poly(3-hydroxybutyric acid)–gelatin nanofibrous scaffold as a soft bio-mimetic material for skin tissue engineering applications

Wound healing is a global health care problem. The use of a suitable dressing material by means of a nanofibrous scaffold with traditionally important medicine can help to repair the damaged skin tissue. An ideal wound dressing material should mimic the function of an extracellular matrix with its improved physiochemical, biological and antimicrobial properties. In this study, the significance features of a collagen coated electrospun poly(3-hydroxybutyric acid)–gelatin nanofibrous scaffold with a bioactive Coccinia grandis extract (CPE) meets the requirements for a wound dressing material. The nanofibrous scaffold with collagen has an attraction for fibroblast, which increases cell adhesion and proliferation. The fabricated nanofibrous scaffold with collagen was characterized physio-chemically using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and it showed acceptable antibacterial property with both Gram positive and Gram negative bacteria. The thermal and in vitro stability of the nanofibrous scaffold was studied and it was found to have stability more than that required for a wound dressing material. The nanofibrous scaffold supports good swelling property with better porosity for oxygen permeability. The mechanical property of the nanofibrous scaffold showed a Youngs modulus of 2.99 ± 0.16 MPa. The biocompatibility of the nanofibrous scaffold exhibits increased cell adhesion and proliferation of both NIH 3T3 fibroblast and human keratinocytes (HaCaT) cell line. The in vitro fluorescence staining of the nanofibrous matrix using Calcein AM and DAPI exhibits the cell material interaction of the collagen coated nanofibrous scaffold corresponding to increased cell adhesion and proliferation. This approach with a nanofibrous scaffold coated with collagen can be a promising tool in skin tissue engineering and can be useful as a wound dressing material in skin tissue engineering applications.

Design and characterization of 3D hybrid collagen matrixes as a dermal substitute in skin tissue engineering

The highly interconnected porous dressing material was fabricated with the utilization of novel collagen (COL-SPG) for the efficient healing of the wound. Herein, we report the fabrication of 3D collagen impregnated with bioactive extract (COL-SPG-CPE) to get rid of infection at the wound site. The resultant 3D collagen matrix was characterized physiochemically using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and mechanical property. The dressing substrate possesses the high swelling ability, increase in the porosity, in vitro enzymatic degradability and antibacterial property. The in vitro biocompatibility and fluorescence activity of the collagen scaffold against both NIH 3T3 fibroblast and Human keratinocyte (HaCaT) cell lines assisted in excellent cell adhesion and proliferation over the collagen matrix. Furthermore, the in vivo evaluation of the COL-SPG-CPE 3D sponge exhibited with enhanced collagen synthesis and aids in faster reepithelialization. However, the rate of wound healing was influenced by the expression of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and transforming growth factor (TGF-β) growth factors promotes the collagen synthesis, thereby increases the healing efficiency. Based on the results, COL-SPG-CPE has a potential ability in the remodeling of the wound with the 3D collagen as wound dressing material.

Durable keratin-based bilayered electrospun mats for wound closure

A bilayered nanofibrous scaffold with rapid wound healing properties is found to be suitable for tissue regeneration applications. The objective of this study is to reveal the fabrication of a poly(3-hydroxybutyric acid) (P)-gelatin (G) nanofibrous mat through electrospinning, with a horn keratin-chitosan-based biosheet (KC) as a bilayered nanofibrous scaffold. The mupirocin (D)-loaded horn KC biosheet (KCD) acts as the primary layer over which PG nanofibers were electrospun to act as the secondary layer. It is shown that this engineered bilayered nanofibrous scaffold material (KC-PG) should fulfill the functions of the extracellular matrix (ECM) by elucidating its function in vitro and in vivo. The bilayered nanofibrous scaffold was designed to exhibit improved physiochemical, biological and mechanical properties, with better swelling and porosity for enhanced oxygen permeability, and it also exhibits an acceptable antibacterial property to prevent infection at the wound site. The bilayered nanofibrous scaffold assists in better biocompatibility towards fibroblast and keratinocyte cell lines. The morphology of the nanofibrous scaffold aids increased cell adhesion and proliferation with cell material interactions. This was elucidated with the help of in vitro fluorescence staining against both cell lines. The bilayered KCD-PG nanofibrous scaffold material gives accelerated wound healing efficiency during in vivo wound healing. The results showed the regulation of growth factors with enhanced collagen synthesis, thereby helping in faster wound healing.

Synthesis, characterization and biological evaluation of chromen and pyrano chromen-5-one derivatives impregnated into a novel collagen based scaffold for tissue engineering applications

In this article, we describe the synthesis and biological evaluation of a novel 2-(methylamino)-3-nitro-4-(4-oxo-4H-chromen-3-yl) pyrano[3,2-c]chromen-5(4H)-one (CCN). It is also determined that CCN impregnated into the collagen scaffold has the potential to mimic the function of the extracellular matrix as a biomaterial in the field of tissue engineering. The series of pyrano[3,2-c]chromen-5(4H)-one derivatives (4a–4j), was analyzed by 1H NMR, 13C NMR, mass spectra and FTIR analysis. Compound 4c was confirmed by single crystal XRD studies. All the compounds were screened for antimicrobial activity against Gram positive, Gram negative bacteria and yeast. Among all the compounds, compound (4aCCN) showed activity against Gram positive and Gram negative bacteria, when compared to the synthesized compounds. Further, compound CCN was evaluated for cytotoxicity against MCF-7, Hep-2 and Vero cancer cell lines with IC50 values of 5.4 μg ml−1, 5.3 μg ml−1 and 68.4 μg ml−1 respectively. In addition, the results of flow cytometry and docking (PDBID: 1A27 with the ligand) studies supported the activity of the synthesized compound (4a). FTIR and NMR analysis of the CCN impregnated collagen scaffold were done to reveal the existence of the CCN molecule in the scaffold. The inherent property of the collagen scaffold was not significantly affected by the structure of the CCN molecule. The thermal and mechanical properties of the collagen scaffold impregnated with CCN molecules gives stability as well as supports the swelling. However, the COL-CCN scaffold showed an enhanced cell attachment and proliferation of NIH 3T3 fibroblast cells. Based on the results, the novel CCN molecule impregnated within a collagen scaffold has potential application as a biomaterial in tissue engineering.

Synthesis of highly interconnected 3D scaffold from Arothron stellatus skin collagen for tissue engineering application.

The substrate which is avidly used for tissue engineering applications should have good mechanical and biocompatible properties, and all these parameters are often considered as essential for dermal reformation. Highly interconnected three dimensional (3D) wound dressing material with enhanced structural integrity was synthesized from Arothron stellatus fish skin (AsFS) collagen for tissue engineering applications. The synthesized 3D collagen sponge (COL-SPG) was further characterized by different physicochemical methods. The scanning electron microscopy analysis of the material demonstrated that well interconnected pores with homogeneous microstructure on the surface aids higher swelling index and that the material also possessed good mechanical properties with a Youngs modulus of 0.89±0.2 MPa. Biocompatibility of the 3D COL-SPG showed 92% growth for both NIH 3T3 fibroblasts and keratinocytes. Overall, the study revealed that synthesized 3D COL-SPG from fish skin will act as a promising wound dressing in skin tissue engineering.

Biomimetic interconnected porous keratin-fibrin-gelatin 3D sponge for tissue engineering application.

The medicated wound dressing material with highly interconnected pores, mimicking the function of the extracellular matrix was fabricated for the promotion of cell growth. In this study, keratin (K), fibrin (F) and gelatin (G) composite scaffold (KFG-SPG) was fabricated by freeze drying technique and the mupirocin (D) drug was successfully incorporated with KFG-SPG (KFG-SPG-D) intended for tissue engineering applications. The fabrication of scaffold was performed without the use of any strong chemical solvents, and the solid sponge scaffold was obtained with well interconnected pores. The porous morphology of the scaffold was confirmed by SEM analysis and exhibited competent mechanical properties. KFG-SPG and KFG-SPG-D possess high level of biocompatibility, cell proliferation and cell adhesion of NIH 3T3 fibroblast and human keratinocytes (HaCaT) cell lines thereby indicating the scaffolds potential as a suitable medicated dressing for wound healing.

Poly (vinyl alcohol) Microspheres Sandwiched Poly (3-hydroxybutyric acid) Electrospun Fibrous Scaffold for Tissue Engineering and Drug Delivery

Three drug delivery systems viz. doxycycline hyclate entrapped poly (vinyl alcohol) (PVA) microspheres (DM), composite fibers of doxycycline hyclatepoly (3-hydroxybutyric acid) (PHB) electrospun fibers (DF), and doxycycline hyclateloaded poly (vinyl alcohol) (PVA) microspheres sandwiched between composite fibers consisting of poly (3-hydroxybutyric acid) (PHB) and doxycycline hyclate (DMF), were developed. The initial burst release studies revealed that DMF drug delivery system developed through suspension electrospinning possessed an optimal initial burst release for wound healing. The developed scaffolds will potentially function in mimicking the extracellular matrix and consecutively enhance healing through its optimal drug release thereby proving its mettle as potential wound dressings for skin regeneration.

Green synthesis of folic acid-conjugated gold nanoparticles with pectin as reducing/stabilizing agent for cancer theranostics

In the present study pectin, a natural polysaccharide was employed for the one pot aqueous synthesis of gold nanoparticles (GNPs). Pectin acted at the same time as both a reducing and stabilizing agent. The formation of pectin reduced GNPs (Pec-GNPs) was confirmed by using a UV-visible spectrophotometer, with a characteristic surface plasmon resonance (SPR) band at 527 nm. EDS analysis proved the presence of gold in the sample. The spherical morphology and crystalline nature of the Pec-GNPs was demonstrated by TEM analysis. The FTIR spectrum revealed the capping of pectin on the surface of the synthesised GNPs. Furthermore, the Pec-GNPs are found to be stable at different pH and electrolytic conditions. In vivo safety of the Pec-GNPs was established through zebra fish toxicity studies. The cationic drug doxorubicin was successfully loaded onto the synthesized anionic Pec-GNPs by an ionic complexation interaction. In vitro release studies confirmed the pH dependent sustained release of the doxorubicin. Doxorubicin loaded Pec-GNPs exhibited enhanced in vitro cytotoxicity on breast cancer cells compared to free doxorubicin, demonstrating that Pec-GNPs are efficient vehicles for the delivery of doxorubicin. Furthermore, chitosan coupled with folic acid (FA) was decorated with Pec-GNPs-DOX as a nanocarrier to improve the targeting and enhance the drug delivery to target cancer tissues by folic acid receptor-mediated endocytosis. It was concluded that the FA@Pec-GNPs-DOX were biocompatible and suitable for anti-cancer drug delivery, and were potentially promising as a new therapeutic system for cancer treatment.

In vivo efficiency of the collagen coated nanofibrous scaffold and their effect on growth factors and pro-inflammatory cytokines in wound healing

ABSTRACT Exploring the importance of nanofibrous scaffold with traditionally important medicine as a wound dressing material prevents infection and aids in faster healing of wounds. In the present study, the Collagen (COL) from the marine fish skin was extracted and employed for coating the Poly(3‐hydroxybutyric acid) (P)–Gelatin (G) nanofibrous scaffold with a bioactive Coccinia grandis extract (CPE) fabricated through electrospinning. Further, the fabricated collagen coated nanofibrous scaffold (PG‐CPE‐COL) applied to the experimental wound of rats and the wound healing was analyzed with by physiochemical and biological techniques. The increased level of hydroxyproline, hexosamine and uronic acid was observed in PG‐CPE‐COL treated than the other groups. The CPE and collagen in the nanofibrous scaffold accelerates the wound healing and thereby reduced the inflammation caused by the cyclooxygenase‐2 (COX‐2) and inducible nitric oxide synthases (iNOS) in wound healing. The nanofibrous scaffold has influenced the expression of various growth factors such as vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and transforming growth factor (TGF‐&bgr;). In addition, the PG‐CPE‐COL nanofibrous scaffold increases the deposition of collagen synthesis and accelerates reepithelialization. Thus, the results suggest that the collagen coated nanofibrous scaffold with bioactive traditional medicine enhanced the faster healing of wound. Graphical abstract Figure. No Caption available.

Facile synthesis and evaluation of quercetin reduced and dextran sulphate stabilized gold nanoparticles decorated with folic acid for active targeting against breast cancer

In the present work, gold nanoparticles (GNPs) were successfully prepared by green synthesis using a strong antioxidant Quercetin (Q) as a reducing agent in the presence of Dextran Sulphate (DS) as a stabilizing agent at room temperature (DS–Q–GNPs). DS–Q–GNPs were characterized by several in vitro techniques to understand their physiochemical and biological properties. However, the average particle size was found to be around 38 nm, and the zeta potential of DS–Q–GNPs was found to be around −42 mV, indicating that the particles were highly stable. TEM results showed that the particles prepared were nearly spherical and crystalline in nature. DS–Q–GNPs exhibited good stability and showed excellent biocompatibility in MTT assay using the NIH 3T3 fibroblast cell line. Similarly, hemocompatibility and in vivo zebra fish toxicity studies confirmed that the DS–Q–GNPs were highly biocompatible and safe in vivo. Doxorubicin (DOX) was successfully loaded on DS–Q–GNPs and decorated with folic acid (FA) for targeting drug delivery to the cancer site (DOX–DS–Q–GNPs–FA). In vitro drug release studies revealed the drug was released in a controlled manner. The anticancer activity of DOX–DS–Q–GNPs–FA against the human breast cancer cell lines (MCF-7) was evaluated using MTT assay. Both doxorubicin loaded GNPs and the free doxorubicin inhibit the growth of MCF-7 cells in a concentration-dependant manner. The enhanced activity of DOX–DS–Q–GNPs–FA against MCF-7 cells was observed with its effect on the cell cycle progression of MCF-7 cells using flow cytometry. Similarly, Western blotting was employed to understand the cell cycle pathways during the treatment of DOX–DS–Q–GNPs–FA. It was found that DOX-loaded DS–Q–GNPs conjugated with FA represent a new potential delivery system for improved cancer therapy.