Research Publications/Outputs

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Browsing Research Publications/Outputs by browse.metadata.impactarea "Advanced Healthcare Materials"

Now showing 1 - 6 of 6
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    2D MXenes nanomaterials for removal of organic wastewater contaminants
    (CRC Press, 2024-12) Mdlalose, Lindani M; Hlekelele, Lerato; Chauke, Vongaini P
    The research and development of two-dimensional (2D) materials was prompted and advanced after the discovery of the remarkable physical properties of single/multiple layered graphene. This hastily encouraged more research on 2D materials in the form of manipulating the structure of graphene through exfoliation, altering the starting material with readily available layered precursors such as graphite-like hexagonal boron nitride or dichalcogenides or even layered oxides [1]. This then stimulated the development of more 2D materials including the birth of MXenes. MXenes are a group 2D transition metal carbides, carbonitrides, and nitrides discovered in 2011 [2]. Their single flakes are denoted by a chemical formula Mn+1 Xn Tx (n = 1 to 4), which designates transition metals alternating layers (M) enclosed by carbon/nitrogen (X) layers with attached terminations Tx (-O2 , -F2 , -OH2 , -Cl2 ) on the external transition metal surfaces [3]. Due to their intriguing electrical and optical properties, they play numerous roles in photodetectors. Additionally, their distinctive mechanical, chemical, and physical properties allow MXenes to be altered by various surface terminations and transition metals. The atomically narrow structure of 2D MXenes makes it an appropriate alternative material for water purification technologies. Additionally, its large surface area, excellent mechanical strength, and numerous functional groups on their surfaces make it a suitable candidate for the uptake of contaminants from aqueous medium [4]. MXenes water purification interest is facilitated by its unique adsorptive, antibacterial, and reductive properties, which are further augmented by high electrical conductivity. With the intensive industrialization and vast agricultural systems, the release of toxic contaminants into ground and surface water continues to be a strain on the environment. In this chapter, the potential use of 2D MXenes derivatives for organic contaminants (such as dyes, antibiotics, and pharmaceuticals) removal is addressed. This entails mechanistic pathways of using MXene-based materials as adsorbents, water purification membranes, and photocatalysts. The ability of MXenebased composites in showing catalytic activity toward diverse pollutants and superior selectivity toward specific pollutants will be discussed.
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    Carboxy-PEG-thiol functionalized gold nanoparticle conjugates for the detection of SARS-CoV-2: Detection tools and analytical method development
    (2024-12) Hlekelele, Lerato; Setshedi, Katlego Z; Mandiwana, Vusani; Kalombo, Lonji; Lemmer, Yolandy; Chauke, Chauke P; Maity, Arjun
    Addressing the need for accessible SARS-CoV-2 testing, carboxy-PEG 12-thiol functionalized gold nanoparticles conjugates were developed for rapid point-of-care (POC) detection against SARS-CoV-2 spike protein, pseudo-SARS-CoV-2, and authentic Beta SARS-CoV-2 virus particles. These conjugates leverage gold nanoparticles (AuNPs) as signal transducers, cross-linked to either angiotensin-converting enzyme 2 (ACE2) or SARS-CoV-2 spike protein receptor-binding domain (RBD) antibodies as bioreceptors and showed a distinct color shift from pink to blue. To assess their POC feasibility, the conjugates were integrated into facemasks and breathalyzers, wherein aerosolized SARS-CoV-2 antigens were successfully detected, producing a color change within 10 and 30 minutes for the breathalyzer and facemask prototypes, respectively. Furthermore, we explored quantitative analysis using varying concentrations of SARS-CoV-2 spike protein. Both conjugates demonstrated a linear relationship between blue color intensity and virus concentration, with linear ranges of 0.08–0.6 ng/mL and 0.04–0.5 ng/mL, respectively. Low limits of detection and quantification were also achieved. They exhibited specificity, responding solely to SARS-CoV-2 even in complex matrices containing diverse proteins, including the SARS-CoV-1 spike protein. Precision tests yielded coefficient of variations below 2 %, showcasing their remarkable reproducibility. This work presents a promising approach for rapid, sensitive, and specific POC detection of SARS-CoV-2 paving the way for improved pandemic response and management.
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    Development and evaluation of Poly(Lactic-Co-Glycolic Acid) encapsulated betulinic acid nanocarrier for improved anti-tumor efficacy
    (2024-12) Selepe, Cyril T; Dhlamini, Khanyisile S; Tshweu, Lesego L; Kwezi, Lusisizwe; Ramalapa, Bathabile E; Ray, Suprakas S
    Betulinic acid (BA) is a promising natural anti-tumor agent renowned for its activity against various tumor cell types. Despite its favorable profile of low cytotoxicity to normal cells, BA’s inherent hydrophobic nature and relatively short systematic half-life impose hurdles for clinical application. This study introduces a strategy to surmount these obstacles by developing a drug delivery system employing poly(lactic-co-glycolic acid) (PLGA)-encapsulated BA nanoparticles (PLGA-BA NPs). Rigorous characterization techniques such as dynamic light scattering (DLS), x-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses are employed to confirm the integrity of the drug within the nanocarriers. The PLGA-BA NPs demonstrated a mean particle size of 196 ± 6.80 nm. XRD analysis demonstrated the amorphous state of the PLGA-BA formulation, a characteristic vital for sustained drug release and enhanced bioavailability. The PLGA-BA NPs exhibited spherical morphology with encapsulation and loading efficiency of 83 ± 9.24% and 7.0 ± 0.4%, respectively, highlighting efficient encapsulation of the drug within the PLGA NPs. In vitro, cytotoxicity assessments demonstrated enhanced anti-proliferative efficacy against breast and lung tumor cells when utilizing PLGA-BA NPs in comparison to free BA. This research underlines the potential of employing the developed PLGA-based nanocarrier to optimize the therapeutic efficacy of BA.
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    Inorganic Ultraviolet Filters in Sunscreen Products: Status, Trends, and Challenges
    (Springer Nature, 2024-07) Hassan Kera, Nazia; Kesavan Pillai, Sreejarani; Ray, Suprakas S
    This book offers a comprehensive overview of recent developments in inorganic ultraviolet (UV) lters utilized for photoprotection applications. It evaluates theperformance of the two approved inorganic UV lters for sunscreen use, titanium dioxide (TiO2) and zinc oxide (ZnO), examining their physicochemical properties in relation to various factors such as ef cacy in UVR attenuation, formulation considerations including product aesthetics and stability, safety aspects, potential risks to human health, and their environmental fate and effects. The regulations governing the use of TiO2 and ZnO in sunscreens are also addressed. Furthermore, the book assesses different modi cation strategies employed to mitigate the undesirable properties of ZnO and TiO2. It also presents various inorganic materials studied as alternatives to ZnO and TiO2, evaluating their potential for use as UV lters. This book is tailored for chemists, material scientists, researchers, engineers (both chemical and biomedical), as well as undergraduate and postgraduate students interested in this dynamic research eld. Additionally, it serves as a valuable resource for industrial researchers and R&D managers aiming to develop and market advanced inorganic UV lter-based sunscreen products.
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    Localized surface plasmon resonance optical biosensor for simple detection of deoxyribonucleic acid mismatches
    (2024) Lugongolo, Masixole Y; Ombinda-Lemboumba, Saturnin; Hlekelele, Lerato; Nyokana, Nontsikelelo; Mthunzi-Kufa, Patience
    Optical biosensors are optical technologies that evaluate changes in the refractive index as they monitor non-covalent molecular interactions in real time. These make use of unsophisticated, label-free analytical approaches, which do not require dyes to produce a visible signal. In this study, the efficiency of localized surface plasmon resonance (LSPR) biosensor in detecting a single nucleotide mismatch in deoxyribonucleic acid is examined. The detection is based on the hybridization of a target DNA at 100 ng μL−1 with a complementary biotinylated probe as well as a partially complementary biotinylated with one nucleotide mismatch probe on a gold-coated surface. Both probes are used at a concentration of 0.1 μm. The LSPR exhibited sensitivity by differentiating sample M+ from sample C+ through varying transmission intensities of 0.28 and 0.26 μA, respectively. Based on these findings, this approach demonstrates a great potential due to its ability to distinguish samples that differ with a single base pair, and its efficiency will be explored in the development of a point-of-care device as a simpler and cost-effective approach for detection of various biologically and medically significant mutations such as antimicrobial resistance mutations. More work is underway to determine the robustness of the LSPR biosensor using the biotin–neutravidin approach.
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    Plant-derived natural products and their nano transformation: A sustainable option towards desert locust infestations
    (2024-11) Mangundu, P; Makaudi, R; Paumo, HK; Ramalapa, Bathabile E; Tshweu, Lesego L; Raleie, N; Katata-Seru, L
    The desert locust has been recognized as the most devastating migratory pest in the world. Swarms of this pest have been threatening vast regions of pastures and crops in Africa, Middle East, and South Asia. The biological management of expanding swarms has become a strategy of particular interest due to environmental awareness and economic issues associated with chemical pesticides. The present review aims to explore the latest updates and information about pesticidal plants that are distributed across Africa. Searches on Web of Science, Google Scholar, PubMed, and Scopus databases from 2013–2024 revealed a total of 22 plant species probed for insecticidal activities against desert locusts. The formulation, active ingredients, and biological effects of essential oils and other extracts from these plants are presented. Despite the promising antiwww.chemistryopen.org [a] [a] Bathabile Ramalapa, [b] insecticidal effects of the plant extracts and compounds, issues related to their solubility and instability under environmental conditions have been observed. To address such major quality defects, methods for the encapsulation of plant natural products within nanostructures are detailed. Given the presence of bioactive compounds with nucleophiles bearing functional groups, the reported plant extracts have been exploited to fabricate metal nanoparticles with inherent insecticidal activities. In this paper, a holistic overview of prepared phytochemical-coated metal nanopesticides is also presented. In summary, this study offers insights into the integration of nanoformulated natural resources as a more sustainable option to control desert locust invasions.