Agnes Aruna John

Tangible nanocomposites with diverse properties for heart valve application

Abstract Cardiovascular disease claims millions of lives every year throughout the world. Biomaterials are used widely for the treatment of this fatal disease. With the advent of nanotechnology, the use of nanocomposites has become almost inevitable in the field of biomaterials. The versatile properties of nanocomposites, such as improved durability and biocompatibility, make them an ideal choice for various biomedical applications. Among the various nanocomposites, polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane, bacterial cellulose with polyvinyl alcohol, carbon nanotubes, graphene oxide and nano-hydroxyapatite nanocomposites have gained popularity as putative choices for biomaterials in cardiovascular applications owing to their superior properties. In this review, various studies performed utilizing these nanocomposites for improving the mechanical strength, anti-calcification potential and hemocompatibility of heart valves are reviewed and summarized. The primary motive of this work is to shed light on the emerging nanocomposites for heart valve applications. Furthermore, we aim to promote the prospects of these nanocomposites in the campaign against cardiovascular diseases.

An insight on electrospun-nanofibers-inspired modern drug delivery system in the treatment of deadly cancers

In spite of ample researches and admirable achievements, there are still a significant number of deaths happening every year due to cancer. Furthermore, the number of new cases recorded is also not reduced despite the advent of various preventive measures. Though current clinical approaches yield commendable results, they elicit severe systemic side-effects and also fail to avoid the recurrence of the disease. To address these issues, nanotechnology-empowered modern drug delivery systems showcase excellent properties for the targeting and controlled delivery of biomolecules over a period of time. In the past decade, the materials-based cancer research field has witnessed the exploration of several attractive drug delivery approaches for the administration of synthetic drugs to genetic materials. Among those, the electrospinning-based nanofibrous mesh has attracted several works on treating common deadly cancers such as those of the lung, breast and colon. The capability of nanofibers to enable increased drug loading, maintenance of significant bioactivity, excellent drug encapsulation, controlled and targeted delivery, has helped the researchers to achieve successful administration of a variety of anti-cancer agents. This review gives an insight into the process of electrospinning, its essential parameters, the types of drug incorporation and the works reported on common deadly cancers. Moreover, the future direction of this effective alternative is also delineated, making electrospun nanofibers as a suitable vehicle for delivering drugs to the cancer sites.

Carbon nanotubes and graphene as emerging candidates in neuroregeneration and neurodrug delivery

Neuroregeneration is the regrowth or repair of nervous tissues, cells, or cell products involved in neurodegeneration and inflammatory diseases of the nervous system like Alzheimer’s disease and Parkinson’s disease. Nowadays, application of nanotechnology is commonly used in developing nanomedicines to advance pharmacokinetics and drug delivery exclusively for central nervous system pathologies. In addition, nanomedical advances are leading to therapies that disrupt disarranged protein aggregation in the central nervous system, deliver functional neuroprotective growth factors, and change the oxidative stress and excitotoxicity of affected neural tissues to regenerate the damaged neurons. Carbon nanotubes and graphene are allotropes of carbon that have been exploited by researchers because of their excellent physical properties and their ability to interface with neurons and neuronal circuits. This review describes the role of carbon nanotubes and graphene in neuroregeneration. In the future, it is hoped that the benefits of nanotechnologies will outweigh their risks, and that the next decade will present huge scope for developing and delivering technologies in the field of neuroscience.

Review: Radiation-induced surface modification of polymers for biomaterial application

The field of biomaterials is one of the fast growing and continuously dominating in medical arena for the last five decades. Biomaterials utilize various kinds of materials ranging from metals, polymers, ceramics and biological substances as an alternative for replacing/assisting the functions of different parts of human system. Major issues associated with biomaterials are their properties and the biocompatibility which have to be addressed and resolved before promoting it to the market or clinical setting. In this scenario, polymers have emerged as a better candidate with versatile properties that make them ideal choice for biomedical applications. However, still the problem of biocompatibility limits the use of polymers in the human body. Several surface modification strategies are continuously evolving to improve the biocompatibility of polymers. This review initially outlines the polymers’ biomedical applications and also elicits the immune aspects of biocompatibility. Further, a thorough attempt is made to summarize the radiation-induced surface modification of the polymers. This review will help us to keep abreast of the recent advances in the radiation-induced surface modification and also in promoting radiation as a probable candidate to enhance the biocompatibility of polymers.

Review: physico-chemical modification as a versatile strategy for the biocompatibility enhancement of biomaterials

A biomaterial can be defined as a material intended to interface with biological systems to evaluate, treat, augment or replace any tissue, organ or function of the body. Major problems associated with biomaterials are their properties and biocompatibility, which need to be tackled and resolved before promoting a particular biomaterial to the market or implanting it into a biological system. To enhance the biocompatibility of the biomaterials, several surface modification strategies, such as physico-chemical, mechanical and biological modifications, have been explored. In this review, some recent applications of physico-chemical modification technologies, such as alteration in the structure of a molecule by chemical modification, surface grafting, abrasive blasting and acid etching, surface coatings, heat and steam treatment for medical materials such as polymers, metals, ceramics and nanocomposites are discussed. This article will promote physico-chemical modification as a versatile technology in surface engineering to improve the properties and biocompatibility of medical materials. Furthermore, it will instigate the growth of the biomaterial market with various high quality biomaterials.

Gallic acid: Prospects and molecular mechanisms of its anticancer activity

Cancer is the second leading cause of death worldwide. There is always a huge demand for novel anticancer drugs and scientists explore various natural and artificial compounds to overcome this. Gallic acid (GA) is one of the phenolic acids found in many dietary substances and herbs used in ancient medicine. It possesses antiinflammatory, antioxidant, antiviral and antibacterial properties. The present review summarizes the anticancer activity of GA and its derivatives. Various in vitro and in vivo experiments of GA against a variety of cancer cell lines were reported. The previous studies show that the anticancer activity of GA is related to the induction of apoptosis through different mechanisms like generation of reactive oxygen species (ROS), regulation of apoptotic and anti-apoptotic proteins, suppression and promotion of oncogenes, inhibition of matrix metalloproteinases (MMPs) and cell cycle arrest depending upon the type of cancer investigated. Conclusively, GA and its derivatives may be considered as a potent drug for cancer treatment alone as well as in combination with other anticancer drugs to increase the efficiency of chemotherapy. However, there is still a need for more experimentation in knock-out animal models and human clinical trials to promote and place GA and its derivatives on the commercial market.

Multifaceted prospects of nanocomposites for cardiovascular grafts and stents

Cardiovascular disease is the leading cause of death across the globe. The use of synthetic materials is indispensable in the treatment of cardiovascular disease. Major drawbacks related to the use of biomaterials are their mechanical properties and biocompatibility, and these have to be circumvented before promoting the material to the market or clinical setting. Revolutionary advancements in nanotechnology have introduced a novel class of materials called nanocomposites which have superior properties for biomedical applications. Recently, there has been a widespread recognition of the nanocomposites utilizing polyhedral oligomeric silsesquioxane, bacterial cellulose, silk fibroin, iron oxide magnetic nanoparticles, and carbon nanotubes in cardiovascular grafts and stents. The unique characteristics of these nanocomposites have led to the development of a wide range of nanostructured copolymers with appreciably enhanced properties, such as improved mechanical, chemical, and physical characteristics suitable for cardiovascular implants. The incorporation of advanced nanocomposite materials in cardiovascular grafts and stents improves hemocompatibility, enhances antithrombogenicity, improves mechanical and surface properties, and decreases the microbial response to the cardiovascular implants. A thorough attempt is made to summarize the various applications of nanocomposites for cardiovascular graft and stent applications. This review will highlight the recent advances in nanocomposites and also address the need of future research in promoting nanocomposites as plausible candidates in a campaign against cardiovascular disease.

Biomaterials based nano-applications of Aloe vera and its perspective: a review

Aloe vera is noted for its meritable medicinal as well as commercial usages. From the past until now, it has been used as a promising remedy for several ailments. Recently, the concept of nanotechnology has astonishingly changed its outlook for biomedical applications. Nanotechnology has revolutionized several fields with its admirable capabilities and ground-breaking innovations. In the field of medicine, nanostructured materials have introduced a great range of flexibility by refashioning traditional practices and also by exploring new effective approaches. Accordingly, the usage of Aloe vera in the form of hydrogels, nanoparticles, nanocomposites, nanofibers and bio-inspired sponges has extended its well established application spectrum in the fields of wound healing, tissue engineering and drug delivery. In addition, the growing interest in consuming and synthesizing materials based on green or eco-friendly methods also highly encourages the use of numerous plant-based natural products including Aloe vera. Hence, an effort has been made to discuss the works related to recent advancements made in the use of Aloe vera, especially in the form of biomaterial-based nanostructures. This will encourage scientists to explore the unplumbed abilities of Aloe vera. Moreover, it will also help the industry players to recognise its immense potential and bring significant Aloe products to the market.

Prospects of common biomolecules as coating substances for polymeric biomaterials

Growing demand for ideal materials in biomedical field not only explores novel approaches, but also examines how existing resources can be modified to fit the requirements. This strategy resulted in the development of various surface modification techniques to improve the biocompatibility of materials already in use. Although various methods are available, the concept of using biological substances for improving biocompatibility seems rational and effective because of the bio-friendly surface that they present which is closer to mimicking the innate environment. Some common biomolecules like proteins, lipids, carbohydrates and peptides are extensively applied on material surfaces through innovative mechanisms. This review will help us to keep abreast of the different types of coating methodologies used and the importance of biological substances as coating alternatives for improving the biocompatibility of polymers. Further, it will also encourage the development of these techniques to modernise materials to make them a more putative choice for biomedical applications.

Evaluation of cardiac signals using discrete wavelet transform with MATLAB graphical user interface

AIM To process the electrocardiogram (ECG) signals using MATLAB-based graphical user interface (GUI) and to classify the signals based on heart rate. METHOD The subject condition was identified using R-peak detection based on discrete wavelet transform followed by a Bayes classifier that classifies the ECG signals. The GUI was designed to display the ECG signal plot. RESULTS Obtained from MIT database 18 patients had normal heart rate and 9 patients had abnormal heart rate; 14.81% of the patients suffered from tachycardia and 18.52% of the patients have bradycardia. CONCLUSION The proposed GUI display was found useful to analyze the digitized ECG signal by a non-technical user and may help in diagnostics. Further improvement can be done by employing field programmable gate array for the real time processing of cardiac signals.