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Surface Engineered Graphene Oxide and Its Derivatives
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Zaira Zaman Chowdhury, Abu Nasser Faisal, Shahjalal Mohammad Shibly, Devarajan Thangadurai, Saher Islam, Jeyabalan Sangeetha
The use of nanoscale materials in biomedical research has elicited exciting findings since they have unique size- and shape-dependent morphology and opto-chemical properties. The higher surface area-to-volume ratio, as well as their distinctive physico-chemical properties, facilitates the development of innovative, surface-engineered structures, and system platform for versatile application (Battigelli et al. 2014). Because of its streamlined, flexible, and scalable structure with tuneable functional groups and porosities, graphene (Gr) and its family of 2D nano-carbon (GO, rGO) has attracted a lot of interest for biomedical applications compared to other nanoparticles (NPs) (Shen et al. 2012; Chen et al. 2015).
Phytoconstituent-Loaded Nanomedicines for Arthritis Management
Published in Mahfoozur Rahman, Sarwar Beg, Mazin A. Zamzami, Hani Choudhry, Aftab Ahmad, Khalid S. Alharbi, Biomarkers as Targeted Herbal Drug Discovery, 2022
Syed Salman Ali, Snigdha Bhardwaj, Najam Ali Khan, Syed Sarim Imam, Chandra Kala
In designing of a proper delivery system, the physicochemical parameters of natural therapeutics and the system are of great importance to understand drug absorption. These properties control the target site action and penetration across the skin due to the presence of metabolic enzymes and skin fencing. Currently, nanomedicines such as liposomes, microspheres, solid lipid nanoparticles (SLNs), nanoemulsions, and microemulsions have been developed to improve the absorption of such bioactive so as to avoid above-mentioned issues (Kostarelos et al., 2003). These systems offer several merits like controlled delivery of drugs (both hydrophobic and hydrophilic in nature), high drug loading (DL) capability, and better suitability in systemic and topical drug delivery. In addition, the nanostructured system provides higher surface area-to-volume ratio, which provides in significant improvement in the pharmacodynamic and pharmacokinetic properties of active drugs on the specific site. A system consisting of small size particles favors better skin interaction and permeation that contributes the extended circulation of drug molecule to specific site via active targeting (Allemann et al., 1999).
Rheology of the Hemolytic Anemias
Published in Gordon D. O. Lowe, Clinical Blood Rheology, 2019
The basic erythrocyte defect in families with hereditary stomatocytosis87 is a failure of regulation of erythrocyte ion and water content caused by an increase in membrane permeability to Na+.88-90 The Na+ influx is greater than the capacity of the Na+/K+ pump so that erythrocyte Na+, water, and volume increase. As the cell adopts the stomatocytic shape, the associated reduction in surface area-to-volume ratio compromises deformability and impairs passage through the spleen. Stomatocytes are unable to pass through 3 μm diameter pores.91 Filtration through 5 μm diameter pores may initially be normal following venepuncture but, after 90 min incubation in autologous plasma in vitro, the stomatocyte shows a rapid loss of filterability owing to the metabolic stresses of hypoglycemia and fall in pH.92 Stomatocytes are more rapidly compromised than normal erythrocytes when depleted of substrate because of the increased energy requirement of the Na+/K+ pump. Similar vulnerability to metabolic stress may occur within the spleen, thus explaining the beneficial effect of splenectomy in some patients.
Hemophagocytic lymphohistiocytosis associated with parvovirus B19-induced aplastic crisis in a hereditary spherocytosis patient: A case report and literature review
Published in Pediatric Hematology and Oncology, 2022
Ki Tae Kim, Kyung Taek Hong, Bo Kyung Kim, Hong Yul An, Jung Yoon Choi, Yoon Hwan Chang, Hyoung Jin Kang
Herein, we report the case of a pediatric patient whose first presentation of HS was HLH. Although aplastic crisis induced by parvovirus is well known in patients with HS, it should be emphasized that HLH can coexist in such situations, although it is rare. HS is characterized by heterogeneous inherited anemia with spherical erythrocytes (spherocytes) on the peripheral blood smear.13–15 This is the most common cause of inherited chronic hemolysis in the Caucasian populations.13 The formation of spherocytes is due to a reduced surface area-to-volume ratio primarily related to the loss of membrane surface area. This is due to the disruption of the membrane skeleton, and splenic destruction of abnormal erythrocytes is the main cause of hemolysis in HS patients.13,14
Release mechanisms and applications of drug delivery systems for extended-release
Published in Expert Opinion on Drug Delivery, 2020
Shuying Wang, Renhe Liu, Yao Fu, W. John Kao
For Equation (5), the device morphology and polymer properties greatly influence the release rate in erodible systems. For example, high surface area to volume ratio of the device accelerates drug release; increasing the size of devices leads to a longer diffusion pathway, resulting in an extended release duration. However, for high molecular weight molecules, the corresponding large hydrodynamic radii would inhibit the diffusion of these molecules through the bulk polymer, thus hindering the continuous release after the initial burst until the breakdown of the dense bulk material to facilitate further drug release. Under this circumstance, additives can be used to overcome the discontinuous release profile [40,41]. Also, several well-established surface-eroding materials with auto-catalytic property could also be utilized [42,43].
Advances in ophthalmic preparation: the role of drug nanocrystals and lipid-based nanosystems
Published in Journal of Drug Targeting, 2020
Maria Christina Camasmie Peters, Edson dos Santos Neto, Lis Marie Monteiro, Megumi Nishitani Yukuyama, Marcella Gabrielle Mendes Machado, Isabela Fernandes de Oliveira, Maria Helena Ambrosio Zanin, Raimar Löbenberg, Nádia Bou-Chacra
Nanocrystals and lipid-based nanosystems are recently available in the market as an innovative strategy for treating ocular ailments. It is noteworthy that there is only one drug nanocrystal product compared to four nanoemulsions for ophthalmic applications. However, drugs nanocrystal have emerged as a powerful approach to improve drug efficacy and safety. This approach increases the surface area to volume ratio of the drug, which increments the drug exposure to biological mucosa. Besides, the increase in the saturation solubility promotes higher drug bioavailability, which presents improved bioadhesiveness when compared to the drug in the micrometric scale. Thus, shortly, drug nanocrystal has the potential to overcome poorly water-soluble drugs, making them trendy for ophthalmic use.