Ketul C Popat

Ketul C Popat
Colorado State University | CSU · Mechanical Engineering

PhD

About

185
Publications
20,838
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7,420
Citations
Introduction
Additional affiliations
December 2007 - July 2020
Colorado State University
Position
  • Professor (Full)

Publications

Publications (185)
Article
Blood compatibility of cardiovascular implants is still a major concern. Rapid endothelialization of these implant surfaces has emerged as a promising strategy to enhance hemocompatibility and prevent complications such as thrombus formation and restenosis. The successful endothelialization of implant surfaces mostly depends on the migration of end...
Article
SARS-CoV-2 is a pandemic coronavirus that causes severe respiratory disease (COVID-19) in humans and is responsible for millions of deaths around the world since early 2020. The virus affects the human respiratory cells through its spike (S) proteins located at the outer shell. To monitor the rapid spreading of SARS-CoV-2 and to reduce the deaths f...
Article
Ecovio® is a hydrophobic, biodegradable, and synthetic polymer blend composed of poly(butylene adipate-co-terephthalate) and poly(acid lactic) polyesters. It is soluble in solvents of low polarity, being a challenge to obtaining thin and homogeneous electrospun Ecovio® fibers. Ecovio® blend solutions do not have electrospinnability due to the low v...
Article
Micro/nano scale surface modifications of titanium based orthopedic and cardiovascular implants has shown to augment biocompatibility. However, bacterial infection remains a serious concern for implant failure, aggravated by increasing antibiotic resistance and over usage of antibiotics. Bacteria cell adhesion on implant surface leads to colonizati...
Article
This study presents an innovative adsorbent material obtained from the dialysis of an aqueous tannin derivative solution, followed by one freezing-thawing cycle at −4°C. The freezing precipitated the tannin (459±97 kDa) in water, yielding the solid adsorbent (d-TN) with aqueous insolubility and stability. The tannin derivative is mainly composed of...
Article
Full-text available
In this work, titania (TiO2) nanoparticles modified by Eu(TTA)3Phen complexes (ETP) were prepared by a simple solvothermal method developing a fluorescence Mn7+ pollutant sensing system. The characterization results indicate that the ETP cause structural deformation and redshifts of the UV-visible light absorptions of host TiO2 nanoparticles. The E...
Article
Ideal wound dressings should be biocompatible, exhibit high antibacterial activity, and promote blood coagulation. To impart these imperative functions, carboxymethyl-kappa-carrageenan was incorporated into poly(vinyl alcohol) nanofibers (PVA-CMKC). The antibacterial activity of the nanofibers was evaluated. Adsorption of two important blood protei...
Article
Full-text available
Global demographic trends have signaled a growing need for biomedical implants such as artificial hips, dental implants, spine screws, coronary stents, and heart pacemakers. The reliability of a manufactured implant can be primarily ensured in terms of its surface integrity, dimensional accuracy, and biocompatibility. In the case of subtractive man...
Article
Human hair can be a sustainable keratin source to prepare cytocompatible drug nanocarriers. A simple and effective methodology to create rod-like keratin nanoparticles (KNPs) using acidic hydrolysis was reported in this work. The extracted KNPs were characterized by infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermal analysis (TG and DSC...
Article
PurposePresent blood-contacting materials have not yet demonstrated to be effective in reducing blood coagulation without causing additional side effects clinically. We have developed an endothelial glycocalyx-inspired biomimetic surface that combines nanotopography, heparin presentation, and nitric oxide (NO)-releasing features. The resulting modi...
Article
Surgical reconstruction of the torn ACL is performed to restore native contact mechanics. Drawbacks to traditional ACL repair techniques motivate the development of a tissue engineered ACL scaffold. Our group has developed a hierarchical electrospun polycaprolactone (PCL) scaffold that consists of rolled nanofiber bundles attached at each end with...
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Full-text available
Tulbaghia violacea plant extracts have been investigated for their potential therapeutic effects in the management of various ailments, among which are cardiovascular diseases, due to the wide range of phytocompounds that the plant possesses. One of the major challenges in clinical practice is the inability to control platelet activation and clotti...
Article
Implant surface plays a crucial role in improving osseointegration and long-term implant life. When the implant comes in contact with the bone tissue, the bone marrow mesenchymal cells interact with the implant surface and the surface properties such as morphology, wettability, mechanical properties and chemistry influences cell migration, prolifer...
Article
Titanium and its alloys are the most used biomaterials for orthopedic and dental applications. However, up to 10% of these medical devices still fail, mostly due to implant loosening and suboptimal integration at the implant site. The biomaterial surface plays a critical role in promoting osseointegration, which can reduce the risk of device failur...
Article
In recent years, studies have been shown that the presence of TiO2 nanotubes on the titanium alloy surfaces could induce the enhancement of the cell adhesion on the titanium alloys surface. In the present study, the cell response of the surface of the Ti-15Zr alloy after TiO2 nanotubes growth (NTs) via anodic oxidation was evaluated. TiO2 NTs were...
Article
Studies investigate the electrospinnability of poly(ε-caprolactone)/protein blends to produce fibers for tissue engineering applications. However, no reports show that zein can improve the scaffolding capacity toward stem cells and promote antiadhesive and bactericidal properties to the poly(ε-caprolactone)/zein fibers. We create fibers with averag...
Article
In this work free-standing gels formed from gellan gum (GG) by solvent evaporation are coated with polysaccharide-based polyelectrolyte multilayers, using the layer-by-layer approach. We show that PEMs composed of iota-carrageenan (CAR) and three different natural polycationic polymers have composition-dependent antimicrobial properties, and suppor...
Article
Biofabrication by three-dimensional (3D) printing has been an attractive technology in harnessing the possibility to print anatomical shaped native tissues with controlled architecture and resolution. 3D printing offers the possibility to reproduce complex microarchitecture of native tissues by printing live cells in a layer by layer deposition to...
Chapter
Medical implants are developed to replace the diseased or fractured hard and soft tissues. Materials scientist and clinicians initially opted for materials which exhibited high strength, non-toxic behaviour and inert as they are not any rejection by the human body. However, with time, the failures of these materials were encountered as their proper...
Article
Thrombosis formation and bacterial infection are key challenges for blood-contacting medical devices. When blood components encounter a device's surface, proteins are adsorbed, followed by the adhesion and activation of platelets as well as an immune response. This culminates in clot formation via the trapping of red blood cells in a fibrin matrix,...
Article
Full-text available
Several studies have been carried out to develop new materials for biomedical applications. Material surfaces that present biomimetic morphology like nanotubes or nanofibers that provides nanoscale architectures have been shown to alter cell/biomaterial interactions. The coated surface biomaterial with biocompatible polymers and nanotubes of TiO 2...
Article
Full-text available
Pectin and chitosan films containing glycerol (Gly) at 5, 10, 15, 20, 30, and 40 wt % were prepared in an aqueous HCl solution (0.10 M) by the solvent evaporation method. The unwashed film (UF) containing 40 wt % Gly (UF40) had elongation at break (ε, %) of 19%. Washed films (WFs) had high tensile strength (σ > 46 MPa) and low elongation at break (...
Article
Full-text available
Titanium and titanium alloys are widely used as a biomaterial due to their mechanical strength, corrosion resistance, low elastic modulus, and excellent biocompatibility. TiO2 nanotubes have excellent bioactivity, stimulating the adhesion, proliferation of fibroblasts and adipose-derived stem cells, production of alkaline phosphatase by osteoblasts...
Article
This study presents a new type of biocompatible nanofiber based on blends of poly(vinyl alcohol) (PVA) and carboxymethyl-kappa-carrageenan (CMKC) blends, produced with no generation of hazardous waste. The nanofibers are produced by electrospinning using PVA:CMKC blends with ratios of 1:0, 1:0.25, 1:0.4, 1:0.5, and 1:0.75 (wt/wt PVA:CMKC) in aqueou...
Article
Incomplete osseointegration is primary cause of failure for orthopedic implants. New biomaterials that present stable signals promoting osteogenesis could reduce failure rates of orthopedic implants. In this study bone morphogenetic protein2 (BMP-2) was delivered fromtitania nanotubes (Nt)modified with chitosan/heparin polyelectrolyte multilayers (...
Article
In this study, a surface modification strategy using natural biopolymers on titanium is proposed to improve bone healing and promote rapid and successful osseointegration of orthopedic implants. Titania nanotubes were fabricated via an anodization process and the surfaces were further modified with polyelectrolyte multilayers (PEMs) based on Tanflo...
Article
In this work, two type of europium (Eu) modified Titania nanotube arrays (TiO2-NTs) are demonstrated. Highly ordered TiO2-NTs were prepared by anodizing the surface of titanium surface at different voltages (30V, 45V, 55V). Eu-doping of TiO2-NTs was carried out by adding Eu³⁺ to the electrolyte during anodization, and Eu-coated TiO2-NTs were obtain...
Article
Hybrid materials, based on bacterial cellulose (BC) and hydroxyapatite (HA), have been investigated for guided bone regeneration (GBR). However, for some GBR, degradability in the physiological environment is an essential requirement. The present study aimed to explore the use of oxidized bacterial cellulose (OxBC) membranes, associated with stront...
Article
In this work, titania nanotube arrays (TiO2-NTs) were prepared by anodization, and the Eu(III) complexes (Eu (TTA)3 phen with 2-thenoyltrifluoroacetone (TTA) and 1, 10-phenanthroline (phen)) were successfully coated onto the walls of the nanotubes. When a solution of glucose, cholesterol or triglycerides was dropped onto Eu(III) complex-modified Ti...
Article
Full-text available
TiO2 nanotubes array gives entirely new types of interactions between titanium surfaces and cells due to the surface area increase and topography that resemble native bone tissue, and has been extensively studied as a promising technique to surface modification of implants. It is also well established that the annealing of anodized titanium surface...
Article
Full-text available
For decades, titanium and its alloys have been established as a biocompatible material for cardiovascular medical devices such as heart valves, stents, vascular grafts, catheters, etc. However, thrombosis is one of the reasons for implant failure, where blood clot forms on the implant surface, thus obstructing the flow of the blood and that leads t...
Article
To develop hemocompatible surfaces, a cationic tannin derivate (TN) was used to prepare polyelectrolyte multilayers (PEMs) with the glycosaminoglycans heparin (HEP) and chondroitin sulfate (CS). The surface chemistry of the PEMs was characterized using X-ray photoelectron spectroscopy and water contact angle measurements. PEMs assembled with chitos...
Article
Full-text available
The polymers poly(ε‐caprolactone) (PCL) has been used in biomaterial field for its relatively inexpensive price and suitability for modification. Also, its chemical and biological properties are desirable on the biomedical application. The electrospinning process has been used for producing polymer fibers of PCL due in large part to an increased in...
Article
Biomaterial-associated thrombosis is still a major concern for blood-contacting implants. After the medical device is implanted and comes in contact with blood, several complex reactions occur, which may lead to thrombus formation and failure of the device. Therefore, it is essential to evaluate the biomaterial interaction with the whole blood. Sev...
Article
Full-text available
A broad range of polymers have been utilized for the development of blood-contacting implantable medical devices; however, their rate of failure has raised the need for developing more hemocompatible biomaterial surfaces. In this study, a novel scaffold based on polycaprolactone incorporated with 10% and 15% (w/w) Tulbaghia violacea plant extracts...
Article
Beta titanium alloys with a low elastic modulus, such as Ti10Mo8Nb alloy, are suitable to relieve the stress shielding effect that occurs in the interface implant/bone. However, these materials are considered bioinert and changing the surface topography is necessary to improve cell adhesion and, consequently, osseointegration. The purpose of this r...
Article
To obtain pectin-based films is challenging due to the aqueous instability of polyelectrolyte mixtures. We overcome this issue by blending chitosan to pectin of high O-methoxylation degree (56%), followed by solvent evaporation. A durable film containing 74 wt% pectin content was produced and used as an adsorbent material toward Cu(II) ions. Kineti...
Article
Chemical modification of polysaccharides is an important route to enhance, develop or change polysaccharide properties. In this study, carboxymethylation of kappa-carrageenan (KC) with monochloroacetic acid was performed to achieve different degrees of substitution (DS) of carboxymethyl-kappa-carrageenan (CMKC). The degree of substitution ranged fr...
Article
Biomaterial‐associated thrombus formation and bacterial infection remain major challenges for blood‐contacting devices. For decades, titanium‐based implants have been largely used for different medical applications. However, titanium can neither suppress blood coagulation, nor prevent bacterial infections. To address these challenges, tanfloc/hepar...
Article
Studies report the production of gold nanoparticles (AuNPs) and polysaccharides-based composites. However, there are few reports about AuNPs synthesis in-situ followed by the formation of hydrogel composites. Here, we show AuNPs synthesis in-situ into the pectin solutions to yield cytocompatible pectin-capped AuNPs/chitosan hydrogel composites. Vis...
Article
The periosteum is a membrane that surrounds bones, providing essential cellular and biological components for fracture healing and bone repair. Tissue engineered scaffolds able to function as periosteum substitutes can significantly improve bone regeneration in severely injured tissues. Efforts to develop more bioactive and tunable periosteal subst...
Article
Physical kappa-carrageenan-based hydrogels are often prepared from dilute aqueous kappa-carrageenan (κ-carrageenan) solutions at the presence of metallic ions or by mixing these solutions with proteins and other polysaccharides. The κ-carrageenan hydrogels have been used for technological purposes; however, there are no reports about the properties...
Article
Full-text available
Tissue engineering has been used for decades to restructure, replace and repair damaged tissue in the body. However, there are a number of challenges that have been identified, with the biggest one currently being the development of scaffolds with the ideal properties that can promote cell-scaffold interactions to enhance cell proliferation and dif...
Article
Virtually all blood-contacting medical implants and devices initiate immunological events in the form of thrombosis and inflammation. Typically, patients receiving such implants are also given large doses of anticoagulants, which pose a high risk and a high cost to the patient. Thus, the design and development of surfaces with improved hemocompatib...
Article
Here, we have demonstrated the production and characterization of hydrogel scaffolds based on chitosan/gellan gum (CS/GG) assemblies, without any covalent and metallic crosslinking agents, conventionally used to yield non-soluble polysaccharide-based materials. The polyelectrolyte complexes (physical hydrogels called as PECs) are characterized by F...
Article
It has been a challenge to develop durable and cytocompatible antibacterial coatings with antiadhesive and antimicrobial activities. To overcome the problems caused by bacteria contamination on biomedical devices, we are proposing layer-by-layer films based on iota-carrageenan/chitosan, and pectin/chitosan polyelectrolyte multilayers (PEMs) assembl...
Article
This study reports the synthesis, characterization and biological properties of films based on poly(vinyl alcohol) (PVA) and a cationic tannin polymer derivative (TN). Films are obtained from polymeric blends by tuning the PVA/TN weight ratios. The materials are characterized through infrared spectroscopy, X-ray photoelectron spectroscopy, contact...
Article
Full-text available
Modifying materials with biocompatible surface coatings is an important method for controlling cell responses to biomaterials. In this work, tanfloc (TN), a cationic tannin-derivative polymer was assembled with heparin (HEP) and chondroitin sulfate (CS), using the layer-by-layer (LbL) approach, to build polyelectrolyte multilayers (PEMs) and to des...
Article
Full-text available
Poly(ε-caprolactone), an aliphatic polyester with biodegradability and cytocompatibility, has been used to create scaffolds for tissue engineering purposes. However, the hydrophobicity and low water absorptivity of poly(ε-caprolactone) reduce cell anchorage on their membranes. Here, poly(ε-caprolactone)-based scaffolds were prepared by electrospinn...
Article
The need to improve blood biocompatibility of medical devices is urgent. As soon as blood encounters a biomaterial implant, proteins adsorb on its surfaces, often leading to several complications such as thrombosis and failure of the device. Therefore, controlling protein adsorption plays a major role in developing hemocompatible materials. In this...
Article
Coronary artery and peripheral vascular diseases are the leading cause of morbidity and mortality worldwide and often require surgical intervention to replace damaged blood vessels, including the use of vascular patches in endarterectomy procedures. Tissue engineering approaches can be used to obtain biocompatible and biodegradable materials direct...
Article
The aim of this work was to evaluate the cellular response to titanium nanotube arrays with variable crystalline structure. Cytotoxicity, viability and the ability of the titania nanotube arrays to stimulate adhesion and proliferation of adipose derived stem cells (ADSCs) was evaluated. Titania nanotube arrays were fabricated by electrochemical ano...
Article
Curcumin (CUR) is a hydrophobic drug which has been loaded into polymeric carrier matrices by using experimental strategies with many steps, as well as by using conventional and volatile organic solvents. For the first time, this study reports the use of an ionic liquid ([Hmim][HSO4⁻]) to solubilize polycation-polyanion polymer pairs and hydrophobi...
Article
When a biomaterial is implanted, the body reacts similar to an injury and stem cells are recruited to the implant site. Since, stem cells play an important role in tissue repair in the body, their interaction with biomaterials is critical for long-term success of medical devices. Surfaces with nanostructured features have been shown to alter cellul...
Article
The surface of an implant is important for successful osseointegration and long-term stability as it can aid in cell migration and proliferation, cell differentiation and allow extracellular matrix production. Earlier studies have shown that nanostructuring the surface of titanium can enhance mesenchymal stem cell (MSC) migration, proliferation, an...
Article
Thrombosis is one of the most critical challenges faced by successful clinical use of blood-contacting medical devices. The formation of blood clots on medical device surfaces is a multistep process that includes protein adsorption, platelet adhesion and activation, and platelet aggregation, resulting in platelet consumption and blockage of blood f...
Article
The anterior cruciate ligament (ACL) acts to stabilize the knee and prevent excessive motion of the tibia relative to the femur. Tears of the ACL are common and can result in pain and damage to surrounding tissues. Thus a torn ACL is often surgically replaced with an autograft or allograft material. Drawbacks to clinically available ACL grafts moti...
Article
Collagen-based materials are probably among the most used class of biomaterials in tissue engineering and regenerative medicine. Although collagen is often privileged for providing a suitable substrate on which cells can be cultured or a matrix in which cells can be dispersed, its mechanical properties represent a major limitation for clinical tran...
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Full-text available
In this study, we investigate the formation of calcium and phosphorus-doped TiO2 nanotubes, produced by potentiostatic anodization of Ti in viscous electrolyte-containing HF and Ca/P ions. Characterization of the produced oxide layer was conducted using scanning electron microscopy, glancing-angle X-ray diffraction, X-ray photoelectron spectroscopy...
Article
Eradication of implant centered infection remains a clinical challenge as the biofilm formation protects the bacteria. Bactericidal surfaces represent an effective tool in the prevention of biofilm formation, although the bactericidal agent cannot be cytotoxic to assure a proper implant osseointegration. Boron is a trace element, beneficial to bone...
Article
Full-text available
In this study, ordered and uniform TiO2 nanotubular structures were obtained on the surface of the Ti15Mo alloy by anodic oxidation. The amorphous state of TiO2 nanotubes formed under different anodization conditions was investigated. Crystallization of TiO2 into anatase phase occurs during annealing at temperatures of around 400°C, whereas anatase...
Article
Full-text available
The purpose of this study is the surface modification of Ti10Mo8Nb experimental alloy by using TiO2 nanostructure growth. Ingots of the Ti10Mo8Nb experimental alloy were produced by fusion from sheets of molybdenum, niobium, and titanium commercially pure in an arc melting furnace under argon atmosphere. The potentiostatic anodic oxidation was perf...
Article
Metallic implants are susceptible to bacterial colonization even years after the implantation impairing the osseointegration process. The treatment of a colonized implant is highly demanding, and in most cases implant replacement is the only effective solution. To avoid the bacterial attachment and proliferation, bactericidal coatings are proposed...
Article
Processing stable polysaccharide membranes with suitable mechanical properties has been challenging for applications in wound healing and tissue engineering. Here we expand the characterization of pectin/chitosan (PT/CS) membranes (without covalent crosslinking), which we recently reported. Membranes containing pectin (PT) excess were formed, and P...
Article
Bulk and surface properties are very important for materials used in biomedical applications. The development of new surface treatments, such as antibacterial coatings can directly affect the response of the surface. The purpose of this study was the development of antibacterial coating on the Ti7.5Mo alloy surface combining TiO2 nanotubes with sil...
Article
Implant centered infections remain as one of the main complications associated with the use of biomedical implants. These infections can be avoided with the development of bactericidal coatings that prevent bacterial contamination since the very early stage of implantation. However, a multifunctional coating should inhibit bacterial contamination w...
Article
Poly(ε-caprolactone) (PCL) is a hydrophobic and cytocompatible aliphatic polyester that has been used to produce PCL-based nanofibrous for both wound healing and tissue repair. However, the high hydrophobicity and low water adsorptive have been challenges for developing PCL-based materials for use in tissue engineering field. Here, we report a new...
Article
Bacterial infections are a serious issue for many implanted medical devices. Infections occur when bacteria colonize the surface of an implant and form a biofilm, a barrier which protects the bacterial colony from antibiotic treatments. Further, the anti-bacterial treatments must also be tailored to the specific bacteria that is causing the infecti...