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Role of Nanotechnology in Tissue Engineering and Regenerative Medicine
Published in Jyoti Ranjan Rout, Rout George Kerry, Abinash Dutta, Biotechnological Advances for Microbiology, Molecular Biology, and Nanotechnology, 2022
Bijayananda Panigrahi, Uday Suryakanta, Sourav Mishra, Rohit Kumar Singh, Dindyal Mandal
The stratum corneum, the outmost layer of keratinized cells, called corneocytes, also a precise skin defensive barrier which is the combination of intracellular lipid and crystalline gel structure, plays the role of mortar between the corneocytes. It is extremely dynamic in lipid enzymatic synthesis and has the capability to acclimate to the environment (Elias and Menon, 1991). Defects are formed by harshly injured skin, which is caused by huge burns or constant wounds. These defects alter the synthesis of the extracellular matrix (ECM) and therefore obstruct the skin’s ability to respire, preserve or drive out water, and defend it against the harmful pathogen, oxidants, and toxins. Therefore, the main function of stratum corneum is to protect from external damage. Skin represents itself as the first layer of defense and also as a boundary wall of the body’s organs. When the skin is injured beyond a certain limit of the total body area, death may result from such damage. Therefore, it is very necessary to immediately cover with dressing which could save from losing the integrity of tissue, homeostasis level, and prevents from toxic materials along with pathogens. The four main objectives that should be cared of a burnt wound are the following: (1) avoid infection, (2) controlling the moist environment around the wound, (3) protect wounds from external aggressions, and (4) reduction of scar formation (Elias and Menon, 1991).
Microneedles: Current Trends and Applications
Published in Tuhin S. Santra, Microfluidics and Bio-MEMS, 2020
Hima Manoj, Pallavi Gupta, Loganathan Mohan, Moeto Nagai, Syrpailyne Wankhar, Tuhin S. Santra
In recent years, drug delivery research has extensively pursued how to transport proteins, DNA, genes, antibodies, and vaccines into cells or tissues safely and efficiently [1–3]. The conventional drug delivery approaches, for example, oral administration and hypodermic injection, exhibit limited functionality owing to the drug inactivation through phase I metabolism during oral delivery and the requirement of a well-trained person for a hypodermic injection. Transdermal drug delivery overcomes these drawbacks, facilitating a safe, easy-to-access, and patient friendly approach. The unfavorable hydrophilicity and large size of biomolecules do not allow passive diffusion across the dermal layers of the skin. The stratum corneum (SC) layer of the skin acts as a barrier against drugs that are lipophobic and large in molecular size, creating complications in the designing of topical formulations. Therefore, various possible options for topical or transdermal delivery systems have been explored to improve drug permeation through the skin, like nanocarrier-loaded topical creams, transdermal patches, and microneedles.
Polymers-Based Devices for Dermal and Transdermal Delivery
Published in Severian Dumitriu, Valentin Popa, Polymeric Biomaterials, 2020
Donatella Paolino, Margherita Vono, Felisa Cilurzo
The skin is the largest organ of our body and represents a unique barrier that protects us from external agents (Hadgraft 2004). It is made up of three main layers, the epidermis (divided into the stratum corneum and the viable epidermis), the dermis, and the hypodermis. In particular, the stratum corneum is characterized by a thickness of 10–20 μm and contains between 10 and 15 layers of corneocytes, which are continually removed and regenerated, while the viable epidermis consists of multiple layers of keratinocytes at various stages of differentiation.
Improved transdermal delivery of valsartan using combinatorial approach of polymeric transdermal hydrogels and solid microneedles: an ex vivo proof of concept investigation
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Cindy Kristina Enggi, Mega Tri Satria, Nirmayanti Nirmayanti, Jesscia Theodor Usman, Julika Fajrika Nur, Rangga Meidianto Asri, Nana Juniarti Natsir Djide, Andi Dian Permana
VAL is a promising candidate to be successfully delivered by transdermal route by having a low molecular weight (434.5 Da) and melting point below 200 °C (116–117 °C) [12]. Moreover, there are no reports of skin irritation caused by VAL [13]. Nevertheless, the log partition coefficient (log P) of VAL is too high (4.5), which limits its permeation through the skin. High log P could cause the drug to be retained in the membrane longer, resulting the inhibition of drugs from being absorbed into the systemic circulation [14]. Besides, the existence of the human skin barrier (stratum corneum) is also one of the main challenges in developing transdermal formulation [15]. The barrier effect of the stratum corneum is most likely caused by its high density and low hydration [8]. Various strategies have been utilized to improve TDDSs, one of which is solid microneedles (SMNs).
Microemulsion and microemulsion gel formulation for transdermal delivery of rutin: Optimization, in-vitro/ex-vivo evaluation and SPF determination
Published in Journal of Dispersion Science and Technology, 2022
Azar Kajbafvala, Alireza Salabat
Transdermal delivery is a convenient route that is noninvasive and painless. Drugs in this type of delivery can reach the target site without arriving at the bloodstream. Also, by eliminating the gastrointestinal pathway, it can avoid drug-drug interactions. Unfortunately, an important barrier named stratum corneum, restricts the permeation of numerous exotic substances through the skin.[1] Over the years, various routes have been employed to enable penetration of drugs into the deeper skin tissues, such as chemical enhancers, physical methods e.g., use of electric voltage or heat,[2] utilization of various drug carriers like liposomes,[3] polymeric nanoparticles,[4] solid lipid nanoparticles (SLNs),[5] nanostructured lipid carriers (NLCs),[6] nanoemulsions[7] and microemulsions.[8–10]
D-optimal design-assisted Elaeis guineensis leaves extract in olive oil-sunflower seed nanoemulsions: development, characterization, and physical stability
Published in Journal of Dispersion Science and Technology, 2022
Nissha Bharrathi Romes, Roswanira Abdul Wahab, Mariani Abdul Hamid, Siti Ernieyanti Hashim
Intrinsic and extrinsic aging processes bring several changes to the appearance of the stratum corneum of the skin, for instance, fine wrinkles, irregular pigmentation, dryness and so forth. Intrinsic aging describes chronological aging due to physiological changes over time, and manifest as loss of elastic tissue and skin thickness, irreversible degeneration of skin tissue, and fewer number of dermal fibroblasts. In contrast, extrinsic aging or photo-aging is elicited by ultraviolet radiation (sunlight), thus turning the skin coarse and rough with deep lines and wrinkles, alongside increased hyperpigmentation.[1,2] To combat such physical changes and protect the skin, consumers have since turned their attention to anti-aging cosmeceuticals to neutralize the harmful effects of free radicals. They prefer cosmeceuticals prepared using natural bioactive ingredients or anti-oxidants of plants and microorganisms origin, etc.[3] In fact, the higher consumer awareness on the fewer side effects of natural ingredients over the chemically manufactured ones, has impacted the current development of cosmeceuticals.