Long-term evaluation of TTK Chitra™ heart valve prosthesis - a retrospective-prospective cohort study.

Purpose: The TTK Chitra™ heart valve has more than 1,40,000 implantations so far, but no long-term data has been published. This study aims to provide long-term results of the valve.

Methodology: A cohort of 476 patients with implantations from January 2006 to December 2018 were followed up prospectively consisting of 104 aortic valve replacement (AVR), 87 double valve replacement (DVR), and 285 mitral valve replacement (MVR) patients.

Evaluation of TTK Chitra heart valve prosthesis in pediatric patients.

This report highlights the outcome of valve replacement using TTK Chitra heart mechanical valve in a subgroup of pediatric patients This cohort of 27 pediatric patients with implantations during January 2006 to December 2018 was followed up prospectively. The cohort consisted of 12 aortic valve replacement (AVR), 14 mitral valve replacement (MVR), and 1 double valve replacement (DVR) patients. Total follow-up was 254 patient-years (AVR = 107, MVR = 136, DVR = 11) being 90% complete.

Nanosecond laser ablation enhances cellular infiltration in a hybrid tissue scaffold.

Hybrid tissue engineered (HTE) scaffolds constituting polymeric nanofibers and biological tissues have attractive bio-mechanical properties. However, they suffer from small pore size due to dense overlapping nanofibers resulting in poor cellular infiltration. In this study, using nanosecond (ns) laser, we fabricated micro-scale features on Polycaprolactone (PCL)-Chitosan (CH) nanofiber layered bovine pericardium based Bio-Hybrid scaffold to achieve enhanced cellular adhesion and infiltration.

Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering.

Major challenge in heart valve tissue engineering for paediatric patients is the development of an autologous valve with regenerative capacity. Hybrid tissue engineering approach is recently gaining popularity to design scaffolds with desired biological and mechanical properties that can remodel post implantation. In this study, we fabricated aligned nanofibrous Bio-Hybrid scaffold made of decellularized bovine pericardium: polycaprolactone-chitosan with optimized polymer thickness to yield the desired biological and mechanical properties.

Hemocompatible curcumin-dextran micelles as pH sensitive pro-drugs for enhanced therapeutic efficacy in cancer cells.

Curcumin, a component in spice turmeric, is renowned to possess anti-cancer therapeutic potential. However, low aqueous solubility and instability of curcumin which subsequently affects its bioavailability pose as major impediments in its translation to clinical application. In this regard, we focused on conjugating hydrophobic curcumin to the hydrophilic backbone of dextran via succinic acid spacer to design a pro-drug.

Engineering of a polymer layered bio-hybrid heart valve scaffold.

Current treatment strategy for end stage valve disease involves either valvular repair or replacement with homograft/mechanical/bioprosthetic valves. In cases of recurrent stenosis/ regurgitation, valve replacement is preferred choice of treatment over valvular repair. Currently available mechanical valves primarily provide durability whereas bioprosthetic valves have superior tissue compatibility but both lack remodelling and regenerative properties making their utility limited in paediatric patients.

Pullulan-histone antibody nanoconjugates for the removal of chromatin fragments from systemic circulation.

The billions of cells that die in the adult human body daily release considerable amounts of fragmented chromatin in the form of mono- and oligonucleosomes into the circulation in normal individuals, and in higher quantities in many disease conditions. Recent results suggest that circulating chromatin fragments (Cfs) especially from abnormal cells can spontaneously enter into healthy cells to damage their DNA and induce genomic instability. Furthermore, Cfs isolated from cancer patients may induce oncogenic transformation in the recipients' cells.

In vitro cytotoxicity and cellular uptake of curcumin-loaded Pluronic/Polycaprolactone micelles in colorectal adenocarcinoma cells.

Clinical application of curcumin has been limited due to poor aqueous solubility and consequently minimal systemic bioavailability. We investigated the preparation of curcumin-loaded micelles based on amphiphilic Pluronic/Polycaprolactone (Pluronic/PCL) block copolymer, which proved to be efficient in enhancing curcumin's aqueous solubility. Curcumin-loaded micelles of size below 200 nm was characterized by dynamic light scattering and transmission electron microscopy.

In vitro cytocompatibility studies of Diamond Like Carbon coatings on titanium.

Diamond like carbon (DLC) films were deposited on to titanium (Ti) substrates by Plasma Enhanced Chemical Vapour Deposition (PECVD) process. The quality of the films were checked by Raman spectra and nano-hardness tests. The cytocompatibility of titanium and DLC coated titanium were studied using continuous cell lines of mouse fibroblast cells ( L-929), Human Osteoblast cells (HOS) and primary human umbilical cord vein endothelial cells (HUVEC).

Quantitation of platelet adhesion to Ti and DLC-coated Ti in vitro using (125)I-labeled platelets.

Measurement of platelet adhesion in vitro is a good indicator of its reactivity to implant devices in vivo. Platelets were labeled with I-125 without affecting its normal morphology and function and the labeled platelets were suspended in platelet poor plasma and exposed to Ti and diamond like carbon-coated (DLC) Ti discs, under dynamic conditions, using a parallel plate flow chamber. The test materials were washed, dried, exposed to a phosphor screen and scanned to get the images.

Long term tissue response to titanium coated with diamond like carbon.

Diamond like carbon (DLC) coatings were deposited on to Ti substrates by plasma enhanced chemical vapor deposition technique. Ti and DLC/Ti samples were implanted in skeletal muscle of rabbits. The samples were explanted after 1, 3, 6 and 12 months and the tissue-cell interaction was studied.

Chitra heart valve: results of a multicenter clinical study.

Background And Aim Of The Study: The Chitra tilting disc valve was developed in India to meet the need for a low-cost cardiac valve. The valve has an integrally machined cobalt-based alloy cage, an ultra-high molecular-weight polyethylene disc, and a polyester suture ring. An important feature of this valve is its soft closing sound, by virtue of a plastic occluder.

Development of the Chitra tilting disc heart valve prosthesis.

Background And Aims Of The Study: The high prevalence of rheumatic valvular disease in the young population and the high cost of imports necessitated the development of an Indian valve. The development of a tilting disc prosthesis was successfully concluded in February 1995, when the third model completed its clinical trial. The tilting disc valve has an integrally machined cobalt alloy cage, an ultra high molecular weight polyethylene disc and a polyester suture ring.

Prevention of calcification of tissue valves.

In this study an attempt was made to find an optimum method of chemical treatment to prevent the calcification of bioprosthetic heart valves. Bovine pericardium was washed in a 5% sodium chloride solution followed by trypsin (Tr) treatment and was kept in 0.1% glutaraldehyde (GA) with a gradual increase in concentration up to 0.

Use of glutaraldehyde-gentamicin-treated bovine pericardium as a wound dressing.

Glutaraldehyde (GA)-pretreated gentamicin post-fixed bovine pericardium has been evaluated as a wound dressing in this study. Two excisions approximately 7 x 4 cm, each of full thickness skin, from the upper and lower parts down to, but not including, the panniculus carnosus were made from the back of the guinea pig. The skin excised from the upper part was placed on the wound bed of the lower part as an autograft, whereas the upper wound was closed using 5% sodium chloride-trypsin-0.

Infrared diameter gauge for in vitro mechanical testing of vascular grafts.

A diameter gauge employing modulated infrared radiation has been developed for in vitro mechanical testing of small diameter vascular grafts. A linear range of greater than 6 mm has been achieved using a 100 mm2 photodiode. The device is immune to ambient illumination.