scholarly journals Natural Polymers in Micro- and Nanoencapsulation for Therapeutic and Diagnostic Applications: Part I: Lipids and Fabrication Techniques

2020 ◽  
Author(s):  
Ndidi C. Ngwuluka ◽  
Nedal Y. Abu-Thabit ◽  
Onyinye J. Uwaezuoke ◽  
Joan O. Erebor ◽  
Margaret O. Ilomuanya ◽  
...  
Keyword(s):  
Superior Performance ◽  
Natural Polymers ◽  
Passive Targeting ◽  
Control Drug ◽  
Diagnostic Agents ◽  
Encapsulation Process ◽  
Bioactive Agents ◽  
Diagnostic Applications ◽  
Sites Of Action ◽  
Control Drug Release

Encapsulation, specifically microencapsulation is an old technology with increasing applications in pharmaceutical, agrochemical, environmental, food, and cosmetic spaces. In the past two decades, the advancements in the field of nanotechnology opened the door for applying the encapsulation technology at the nanoscale level. Nanoencapsulation is highly utilized in designing effective drug delivery systems (DDSs) due to the fact that delivery of the encapsulated therapeutic/diagnostic agents to various sites in the human body depends on the size of the nanoparticles. Compared to microencapsulation, nanoencapsulation has superior performance which can improve bioavailability, increase drug solubility, delay or control drug release and enhance active/passive targeting of bioactive agents to the sites of action. Encapsulation, either micro- or nanoencapsulation is employed for the conventional pharmaceuticals, biopharmaceuticals, biologics, or bioactive drugs from natural sources as well as for diagnostics such as biomarkers. The outcome of any encapsulation process depends on the technique employed and the encapsulating material. This chapter discusses in details (1) various physical, mechanical, thermal, chemical, and physicochemical encapsulation techniques, (2) types and classifications of natural polymers (polysaccharides, proteins, and lipids) as safer, biocompatible and biodegradable encapsulating materials, and (3) the recent advances in using lipids for therapeutic and diagnostic applications. Polysaccharides and proteins are covered in the second part of this chapter.

Microencapsulation and Nanoencapsulation: A Review

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
V. Suganya ◽  
V. Anuradha
Keyword(s):  
Drug Release ◽  
New Technology ◽  
Inert Material ◽  
Food Industries ◽  
Control Drug ◽  
Advantages And Disadvantages ◽  
Nano Scale ◽  
Pharmaceutical Industries ◽  
The Difference ◽  
Control Drug Release

Encapsulation is a process of enclosing the substances within an inert material which protects from environment as well as control drug release. Recently, two type of encapsulation has been performed in several research. Nanoencapsulation is the coating of various substances within another material at sizes on the nano scale. Microencapsulation is similar to nanoencapsulation aside from it involving larger particles and having been done for a greater period of time than nanoencapsulation. Encapsulation is a new technology that has wide applications in pharmaceutical industries, agrochemical, food industries and cosmetics. In this review, the difference between micro and nano encapsulation has been explained. This article gives an overview of different methods and reason for encapsulation. The advantages and disadvantages of micro and nano encapsulation technology were also clearly mentioned in this paper.

scholarly journals The ABCG2 multidrug transporter is a pump gated by a valve and an extracellular lid

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Narakorn Khunweeraphong ◽  
Daniel Szöllősi ◽  
Thomas Stockner ◽  
Karl Kuchler
Keyword(s):  
Drug Release ◽  
Molecular Mechanism ◽  
Salt Bridge ◽  
Multidrug Transporter ◽  
Peristaltic Pump ◽  
Disulfide Bridges ◽  
Control Drug ◽  
Atp Binding Cassette Transporter ◽  
Extracellular Loops ◽  
Control Drug Release

AbstractThe human ATP-binding cassette transporter ABCG2 is a key to anticancer resistance and physiological detoxification. However, the molecular mechanism of substrate transport remains enigmatic. A hydrophobic di-leucine motif in the ABCG2 core separates a large intracellular cavity from a smaller upper cavity. We show that the di-leucine motif acts as a valve that controls drug extrusion. Moreover, the extracellular structure engages the re-entry helix and all extracellular loops to form a roof architecture on top of the upper cavity. Disulfide bridges and a salt bridge limit roof flexibility, but provide a lid-like function to control drug release. We propose that drug translocation from the central to the upper cavities through the valve is driven by a squeezing motion, suggesting that ABCG2 operates similar to a peristaltic pump. Finally, the roof contains essential residues, offering therapeutic options to block ABCG2 by either targeting the valve or essential residues in the roof.

scholarly journals Organic Functionalization of Mesoporous Silica Spheres as a Nanovehicle for DOX pH-Triggered Delivery

NANO ◽  
2019 ◽  
Vol 14 (08) ◽  
pp. 1950094 ◽  
Author(s):  
Shuai Wang ◽  
Fang Xiang Song ◽  
Li Zhang ◽  
Xue Zhang ◽  
Yan Li
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Mesoporous Silica ◽  
A549 Cells ◽  
Carboxyl Groups ◽  
Organic Functionalization ◽  
Control Drug ◽  
Potential Applications ◽  
Control Drug Release ◽  
Mesoporous Silica Spheres

Mesoporous silica (MS) spheres of different sizes with pH-responsive characteristics were synthesized based on Stöber’s theory. Organic functionalization with aminopropyl and carboxyl groups resulted in different materials, namely, MS@NH2@COOH. MS@NH2@COOH were observed to have a large number of carboxyl groups and multiamine chains, and were grafted into pore channels and pore outlets through systematic characterization analyses. All modified samples demonstrated the controlling of the delivery rate of DOX from the siliceous matrix. We also compared the drug release behavior of the DOX-loaded materials at high pH (7.4) and low pH (5.5) and studied the cytotoxicity on A549 cells. The experimental results indicated that the drug delivery system can better control drug release and have potential applications in the drug delivery field.

scholarly journals Silk fibroin/polyethylene glycol nanofibrous membranes loaded with curcumin

2017 ◽  
Vol 21 (4) ◽  
pp. 1587-1594 ◽  
Author(s):  
Qing Liu ◽  
Shufa Zhou ◽  
Zeyu Zhao ◽  
Ting Wu ◽  
Rong Wang ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Drug Release ◽  
Silk Fibroin ◽  
Drug Loading ◽  
Control Drug ◽  
Nanofiber Membranes ◽  
Utilization Ratio ◽  
The Stability ◽  
Control Drug Release

In order to improve the stability, utilization ratio and anti-tumor effect of curcumin drug, a set of curcumin-loaded nanofiber membranes with drug releasing property were fabricated using silk fibroin and polyethylene glycol. Various curcumin-loaded silk fibroin nanofiber membranes with different components and drug loading percentages were prepared using electrospinning technology. The morphology structure, mechanical properties, secondary structure, drug release property in vitro, and their interaction effects of the curcumin-loaded silk fibroin nanofiber membranes were examined. The result of in-vitro drug release experiment showed that the curcumin can be released stably up to 350 hours, the drug releasing speed increased with the decrease of the diameter of the fibers. The stability and utilization ratio of curcumin was improved after loading with curcumin-loaded silk fibroin nanofiber membranes. In conclusion, it can be used as a control drug release system alternately in the future.

Biodegradable Polymers as Matrices for Control Drug Delivery

2014 ◽  
Vol 911 ◽  
pp. 336-341 ◽  
Author(s):  
Maria Mucha ◽  
Iwona Socha-Michalak ◽  
Jacek Balcerzak
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Transport ◽  
Buffer Solution ◽  
First Order ◽  
Control Drug ◽  
Buffer Solutions ◽  
Control Drug Release ◽  
Control Drug Delivery ◽  
Active Substances

In the paper the results of control drug release from different forms of carriers are presented. Dibutyrylchitin, chitosan, polylactid acid and polycaprolactone have been used as matrices for delivery of therapeutic substances (ibuprofen and salicylic acid). Two configurations of matrices for drug delivery have been found. Flat drug delivery systems (films) and spherical matrices (beads) were tested in the aim of control drug transport. To control the drug release, matrices have been modified. The release of active substances from films has been tested in buffer solution of pH 5.5. Spherical matrices have been tested in buffer solutions of pH 1.4 and pH 7.2. To experimental data First order and two stage models were fitted.

Chitosan/alginate based multilayers to control drug release from ophthalmic lens

2016 ◽  
Vol 147 ◽  
pp. 81-89 ◽  
Author(s):  
Diana Silva ◽  
Luís F.V. Pinto ◽  
Dimitriya Bozukova ◽  
Luís F. Santos ◽  
Ana Paula Serro ◽  
...  
Keyword(s):  
Drug Release ◽  
Control Drug ◽  
Control Drug Release

Inkjet printing based assembly of thermoresponsive core–shell polymer microcapsules for controlled drug release

2016 ◽  
Vol 4 (23) ◽  
pp. 4156-4163 ◽  
Author(s):  
Jianmin Yang ◽  
Daisuke Katagiri ◽  
Sifeng Mao ◽  
Hulie Zeng ◽  
Hizuru Nakajima ◽  
...  
Keyword(s):  
Drug Release ◽  
Inkjet Printing ◽  
Shell Structure ◽  
Controlled Drug Release ◽  
Core Shell ◽  
Hollow Core ◽  
Thermoresponsive Polymer ◽  
Porous Shell ◽  
Control Drug ◽  
Control Drug Release

A thermoresponsive polymer microcapsule with a hollow core–porous shell structure was fabricated based on inkjet printing, which can be used to control drug release by changing the temperature at around 38 °C.

scholarly journals Controlled Release of Benzocaine from Monomer and Copolymer Carriers in Synthetic Gastro-intestinal Media

2014 ◽  
Vol 3 (2) ◽  
pp. 853
Author(s):  
Houaria Merine ◽  
Abderrezzak Mesli ◽  
Nafa Chafi ◽  
Zohra Bengharez
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Condensation Reaction ◽  
Average Molecular Weight ◽  
Aqueous Media ◽  
Control Drug ◽  
Elemental Analyses ◽  
Intestinal Fluids ◽  
Fraction I ◽  
Control Drug Release

<p class="Default">New dosage forms able to control drug release in the gastro-intestinal media have been prepared and investigated in this paper. Two different type of medicinal agent bonding (MA), in our case Benzocaine (Bz), were chosen in order to examine drug release.</p><p class="Default">i) MA attached to ethylenic monomer (m,p-vinylbenzaldehyde), condensation reaction.</p><p class="Default">ii) The copolymer carrier (Cp) is obtained by copolymerizing this monomer.</p><p class="Default">These two carriers were well characterized by microanalysis, FTIR, DSC (Tg) and GPC (Ip) and the two fraction α and β were calculated from elemental analyses of Cp. The results showed good polydispersity and low average molecular weight. MA linked to an organic product by the azomethine function (C=N), hydrolytically sensitive, allowed controlled release of Bz, from the monomer carrier and from the bending Schiff bases groups. Theoretical and experimental analyses of controlled release of Bz kinetics from monomer and copolymer carriers were conducted for the case of contact with synthetic gastro-intestinal fluids at various pH (1,2; 6,0 and 8,0) at 37°C.</p><p class="Default">The process was found to be controlled by the nature of media (heterogeneous), which involved the preliminary hydrolysis, and the drug (Bz) diffusing out of structure of copolymer (Cp) to the external aqueous media.</p><p class="Default">The results obtained on the rate of delivery showed a clear difference between pH = 1,2 and pH = 6,0 and 8,0 based on:</p><p class="Default">i) The cation of p-aminoniumbenzoic acid (PABAH+) release at pH = 1,2</p><p class="Default">ii) Bz release at pH = 6,0 and 8,0</p>

Sign in / Sign up

Export Citation Format

Share Document