Thiol‐yne 3D Printable Polymeric Resins for the Efficient Removal of a Model Pollutant from Waters

Abstract A new 3D printable resin formulation is developed and optimized from commercially available thiol (pentaerythritol tetrakis(3‐mercaptopropionate); PETMP) and alkyne (3‐butyn‐1‐ol; BA) monomers. Printed objects are characterized by Fourier‐transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The extraction efficiency of the printed thiol‐yne device is then investigated using a model dye – malachite green (MG). The results displayed excellent dye removal efficiency with > 95% MG removed within 5 min. The 3D‐printed devices are reusable and show 100% removal over six cycles after washing with deionized water and methanol. The presence of surface hydroxyl groups derived from the BA monomer is shown to enhance dye adsorption in comparison to control materials. The printing procedure and resin formulation are robust and consistent when devices from different resin batches are compared for MG dye removal. The thiol‐yne 3D printed devices demonstrated excellent dye removal (> 99%) from water samples collected from a tap and a nearby river source. The successful development of this resin provides a new thiol‐yne‐based resin system for stereolithography (SLA) 3D printing for the removal of organic dyes from wastewater and presents a potential for broad applications in water treatment

Identification of anti-cancer potential of doxazocin:Loading into chitosan based biodegradable hydrogels for on-site delivery to treat cervical cancer

In this study, an effective, biocompatible and biodegradable co-polymer comprising of chitosan (CS) and polyvinyl alcohol (PVA) hydrogels, chemically crosslinked and impregnated with doxazocin, is reported. The chemical structural properties of the hydrogels were evaluated by Fourier Transform Infrared spectroscopy (FTIR) and physical properties were analysed by scanning electron microscopy (SEM). The swelling behaviour is an important parameter for drug release mechanism and was investigated to find out the solution absorption capacity of the synthesized hydrogels. MTT assay revealed that doxazocin loaded hydrogels significantly hindered the cell viability. Flow cytometry analysis was performed to analyse the effect of 8CLH and 4CLH on regulation of cell cycle. Moreover, in vivo anti-cancer potential of synthesized hydrogels was assessed by CAM Assay. Results displayed that 8CLH with 1 mg/ml of doxazocin had prominently decreased the angiogenesis and significantly increased the number of cells in G1 phase of cell cycle. These results declared that 8CLH will be a good addition among hydrogels used for treatment of cancer by onsite delivery of drug

Thyroxin releasing chitosan/collagen based smart hydrogels to stimulate neovascularization

The development of new biomaterials with tailored properties is highly desired in tissue engineering field. The neovascularization is essential part of tissue regeneration which provides food and nutrients to cells. There is a real need for proangiogenic biomaterials to assist wound healing. The ideal dressing should be inexpensive and achieve rapid healing with minimal inconvenience to the patient. In this paper, new porous thyroxin containing pro-angiogenic hydrogels were generated via freeze gelation protocol. The chemical structural analysis of the synthesized hydrogels was investigated by Fourier Transform Infrared (FTIR) spectroscopy. The morphology and pore dimensions were studied by scanning electron microscopy (SEM). In swelling studies, 10 μg thyroxine loaded hydrogel (TLH-10) showed greater degree of swelling as compared to 1 μg loaded thyroxine material (TLH-1) and control. The degradation studies were tested in three different media, i.e. phosphate buffer saline (PBS), lysozyme and hydrogen peroxide and relatively higher degradation was seen in hydrogen peroxide. The synthesized materials were implanted on the chick chorioallantoic membrane to investigate their angiogenic potential. The TLH-1 hydrogel stimulated angiogenesis greater than the TLH-10; in this case blood vessels were attached and very much grown into the scaffold

Heparin binding chitosan derivatives for production of pro-angiogenic hydrogels for promoting tissue healing

Our aim was to develop a biocompatible hydrogel that could be soaked in heparin and placed on wound beds to improve the vasculature of poorly vascularized wound beds. In the current study, a methodology was developed for the synthesis of a new chitosan derivative (CSD-1). Hydrogels were synthesized by blending CSD-1 for either 4 or 24 h with polyvinyl alcohol (PVA). The physical/chemical interactions and the presence of specific functional groups were confirmed by Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance (1H NMR). The porous nature of the hydrogels was confirmed by scanning electron microscopy (SEM). Thermal gravimetric analysis (TGA) showed that these hydrogels have good thermal stability which was slightly increased as the blending time was increased. Hydrogels produced with 24 h of blending supported cell attachment more and could be loaded with heparin to induce new blood vessel formation in a chick chorionic allantoic membrane assay

Novel chitosan derivative based composite scaffolds with enhanced angiogenesis; potential candidates for healing chronic non-healing wounds

The success of wound healing depends upon the proper growth of vascular system in time in the damaged tissues. Poor blood supply to wounded tissues or tissue engineered grafts leads to the failure of wound healing or rejection of grafts. In present paper, we report the synthesis of novel organosoluble and pro-angiogenic chitosan derivative (CSD) by the reaction of chitosan with 1,3-dimethylbarbituric acid and triethylorthoformate (TEOF). The synthesized material was characterized by FTIR and 13C-NMR to confirm the incorporated functional groups and new covalent connectivities. Biodegradability of the synthesized chitosan derivative was tested in the presence of lysozyme and was found to be comparable with CS. The cytotoxicity and apoptosis effect of new derivative was determined against gastric adenocarcinoma (AGS) cells and was found to be non-toxic. The CSD was found to be soluble in majority of organic solvents. It was blended with polycaprolactone (PCL) to form composite scaffolds. From an ex ovo CAM assay, it was noted that CSD stimulated the angiogenesis. [Figure not available: see fulltext.]. © 2019, Springer Science+Business Media, LLC, part of Springer Nature

An efficient new method for electrospinning chitosan and heparin for the preparation of pro‐angiogenic nanofibrous membranes for wound healing applications

Chronic skin wounds and surgical sutures need critical care and fast recovery, robust connection of blood vessels and effective restoration of circulation is necessary in progressive wound healing. Heparin is well known for its' anticoagulant properties, VEGF activation and antithrombosis action. Chitosan aid in the development of the vascular grafts due to its ECM like properties of blood vessels. For electrospinning of Heparin negatively charged and low molecular weight positively charges chitosan, the homogenous solution is required, they precipitate out during mixing due to opposite charges. In the current study, a an efficient strategy is developed for the electrospinning of chitosan and heparin in the presence of lysozyme. The insolubility/non-homogenous solution formation for electrospinning from charged chitosan and heparin fast acting was solved by using a small amount of N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB) and the resulting solution produced very smooth nanofibers. Polycaprolactone (PCL) was found to be a suitable polymer for the electrospinning of chitosan and heparin using organic and inorganic solvents. Surface morphology of the synthesized fibers was investigated by scanning electron microscopy (SEM) and the presence of functional groups was investigated by FTIR. Degradation studies were performed which revealed that lysozyme loaded materials were degraded much faster as compared to other materials. The angiogenic and biocompatible potential of heparin with 1 mg/ml and 4 mg/ml lysozyme concentration was demonstrated by chorionic allantoic membrane (CAM) assay and it was estimated that 1 mg/ml (lysozyme) loaded CS/HA material was found to be an efficient biomaterial to stimulate angiogenesis

Development of K-doped ZnO nanoparticles encapsulated crosslinked chitosan based new membranes to stimulate angiogenesis in tissue engineered skin grafts

Nanoparticles are well recognized for their biological applications including tissue-regeneration due to large surface area and chemical properties. In this study, K-doped zinc oxide (ZnO) nanoparticles containing porous hydrogels were synthesized via freeze gelation. The morphology and pore dimensions were studied by scanning electron microscopy (SEM). The chemical structural analysis of the synthesized hydrogels was investigated by Fourier Transform Infrared (FTIR) spectroscopy. In swelling studies, material containing ZnO nanoparticles with 2% potassium dopant concentration CLH-K2.0) showed greater degree of swelling as compared to all other materials. The degradation studied was tested in three different degradation media, i.e. phosphate buffer saline (PBS), lysozyme and hydrogen peroxide and relatively higher degradation was seen in hydrogen peroxide. The synthesized hydrogels were implanted on the chick chorioallantoic membrane (CAM) to investigate their angiogenic potential. The CLH-K2.0 hydrogel stimulated angiogenesis greater than all other materials; blood vessels were attached and grown inside this scaffold, showing its strong angiogenic potential