Permeability and capillary radius of the skin layer

2022 ◽  
pp. 527-528
Keyword(s):  
1997 ◽  
Vol 35 (8) ◽  
pp. 137-144 ◽  
Author(s):  
Tsuyoshi Nomura ◽  
Takao Fujii ◽  
Motoyuki Suzuki

Porous membrane of poly(tetrafluoroethylene) (PTFE) was formed on the surface of porous ceramic tubes by means of heat treatment of the PTFE particles deposit layer prepared by filtering PTFE microparticles emulsified in aqueous phase. By means of inert gas permeation, pore size was determined and compared with scanning electron micrograph observation. Also rejection measurement of aqueous dextran solutions of wide range of molecular weights showed consistent results regarding the pore size. Since the membrane prepared by this method is stable and has unique features derived from PTFE, it is expected that the membrane has interesting applications in the field of water treatment. Membrane separation of activated sludge by this composite membrane and original ceramics membrane showed that the PTFE membrane gives better detachability of the cake layer formed on the membrane. This might be due to the hydrophobic nature of the PTFE skin layer.


2020 ◽  
Vol 15 (4) ◽  
pp. 283-298
Author(s):  
Suresh Kumar Sahu ◽  
Rakesh Raj ◽  
Pooja Mongia Raj ◽  
Ram Alpana

Treatment of skin ailments through systemic administration is limited due to toxicity and patients discomfort. Hence, lower risk of systemic side effects from topical dosage forms like ointments, creams, emulsions and gels is more preferred for the treatment of skin disease. Application of lipid based carriers in drug delivery in topical formulations has recently become one of the major approaches to improve drug permeation, safety, and effectiveness. These delivery systems include liposomes, ethosomes, transfersomes, Nanoemulsions (NEs), Solid Lipid Nanoparticles (SLNs) Nanostructured Lipid Carriers (NLCs) and micelles. Most of the liposomes and SLNs based products are in the market while some are under investigation. Transcutaneous delivery of therapeutics to the skin layer by novel lipid based carriers has enhanced topical therapy for the treatment of skin ailments. This article covers an overview of the lipid-based carriers for topical uses to alleviate skin diseases.


2020 ◽  
Vol 14 (3) ◽  
pp. 169-186
Author(s):  
Marwa Emam ◽  
Akaber T. Keshta ◽  
Yasser M.A. Mohamed ◽  
Yasser A. Attia

Background: Wound healing is a complex process necessary for repairing damaged tissues and preventing infection. Selenium nanoparticles (Se NPs) were known due to their antioxidant and antimicrobial effects, also niacin has angiogenesis and antioxidant effects that are important in wound healing. Objective: The present study was conducted to investigate the effect of Se NPs and niacin in reducing and accelerating the wound healing time in mice. Methods: A simple wet chemical method has been modified to synthesize Se NPs in order to investigate their effect and niacin on reducing the wound healing in 80 adult female albino mice (250 mm2 full thickness open excision wound) that were divided into eight groups (10 mice/each). After 30-days, the mice were sacrificed, blood and tissue samples were taken for analysis. Results: The results showed that the percentage of wound area had been significantly reduced in Se NPs and niacin treated groups compared to the positive control. The level of Vascular Endothelial cell Growth Factor and Collagenase I in Se NPs and niacin groups significantly exceed those of other groups while Nitric Oxide (NO) was significantly decreased in treated groups. Liver and kidney functions showed the lower toxicity effect of Se NPs and niacin. Skin tissue showed the wound healing effect of Se NPs and niacin by regenerating skin layer compared to the positive group. Conclusion: Se NPs and niacin play an important role in accelerating and reducing the time of wound healing while they were antagonistic to each other.


2021 ◽  
pp. 096739112098650
Author(s):  
Dah Hee Kim ◽  
Young Seok Song

The purpose of this study is to integrate a polymeric film onto a mold to impede thermal heat transfer during resin infusion. A thin plastic plate was fabricated by using microinjection molding. A polyimide (PI) film was laminated onto a mold in an effort to produce a thin light guide plate (LGP). The film could decelerate the solidification of molten polymer in the cavity of mold and enhance the wall slip of resin on the mold. The insulation effect was modeled numerically. The surface roughness and pattern transfer characteristics of the LGP were evaluated. It was found that the fluidity of the resin increased due to the decreased skin layer during mold filling. The results showed that the strategy proposed in this study could help decrease the thickness of LGP effectively when manufacturing the part via injection molding.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 923
Author(s):  
Shadab Md ◽  
Nabil A. Alhakamy ◽  
Hibah M. Aldawsari ◽  
Mohammad Husain ◽  
Nazia Khan ◽  
...  

Plumbagin (PLM) is a phytochemical which has shown cytotoxicity against of cancer cells both in vitro and in vivo. However, the clinical application of PLM has been hindered due to poor aqueous solubility and low bioavailability. The aim of the present study was to develop, optimize and evaluate PLM-loaded glycerosome (GM) gel and compare with conventional liposome (CL) for therapeutic efficacy against skin cancer. The GM formulations were optimized by employing design expert software by 3-level 3-factor design. The prepared GMs were characterized in vitro for vesicle size, size distribution, zeta potential, vesicle deformability, drug release, skin permeation, retention, texture, antioxidant and cytotoxicity activities. The optimized formulation showed a vesicle size of 119.20 ± 15.67 nm with a polydispersity index (PDI) of 0.145 ± 0.02, the zeta potential of −27 ± 5.12 mV and entrapment efficiency of 76.42 ± 9.98%. The optimized PLM-loaded GM formulation was transformed into a pre-formed gel which was prepared using Carbopol 934 polymer. The drug diffusion fluxes of CL gel and GM-loaded gel were 23.31 ±6.0 and 79.43 ± 12.43 µg/ cm2/h, respectively. The result of texture analysis revealed the adequate hardness, cohesiveness, consistency, and viscosity of the developed GM-loaded gel compared to CL gel. The confocal images showed that glycerosomal gel has deeper skin layer penetration as compared to the control solution. GM-loaded gel treated rat skin showed significantly (p < 0.05) higher drug accumulation in the dermis, higher cytotoxicity and higher antioxidant activity as compared to CL gel and PLM suspension. Thus, findings revealed that novel GM-loaded gel could be potential carriers for therapeutic intervention in skin cancer.


2006 ◽  
Vol 24 (2) ◽  
pp. 249-254 ◽  
Author(s):  
J. BADZIAK ◽  
S. GŁOWACZ ◽  
H. HORA ◽  
S. JABŁOŃSKI ◽  
J. WOŁOWSKI

The properties of plasma (proton) block driven by the laser-induced skin-layer ponderomotive acceleration (S-LPA) mechanism are discussed. It is shown that the proton density of the plasma block is about a thousand times higher than that of the proton beam produced by the target normal sheath acceleration (TNSA) mechanism. Such a high-density plasma (proton) block can be considered as a fast ignitor of fusion targets. The estimates show that using the S-LPA driven plasma block, the ignition threshold for precompressed DT fuel can be reached at the ps laser energy ≤ 100 kJ.


Aerospace ◽  
2006 ◽  
Author(s):  
K. Ahlers ◽  
K. P. Hallinan ◽  
B. Sanders ◽  
R. McCarty

The Entropy Generation Minimization (EGM) approach is applied to the design of a new integrated radar aircraft skin, which both meets requisite aircraft structural needs and provides a pathway for the waste heat from structurally integrated power devices. Thermoelectric (TE) devices, sandwiched between a heterogeneous skin layer and the radar devices for the purpose of harvesting waste heat rejected to the ambient, are considered in the analysis. A heterogeneous skin layer is designed using the EGM approach, which is then applied to the overall mission of the aircraft to determine the optimal skin thickness and volume fractions of the matrix and inclusions in the composite skin.


Sign in / Sign up

Export Citation Format

Share Document