scholarly journals Multiresponsive Hybrid Microparticles for Stimuli-Responsive Delivery of Bioactive Compounds

2020 ◽  
Vol 10 (12) ◽  
pp. 4324 ◽  
Author(s):  
Sergei S. Vlasov ◽  
Pavel S. Postnikov ◽  
Mikhail V. Belousov ◽  
Sergei V. Krivoshchekov ◽  
Mekhman S. Yusubov ◽  
...  

Hybrid microparticles based on an iron core and an amphiphilic polymeric shell have been prepared to respond simultaneously to magnetic and ultrasonic fields and variation in the surrounding pH to trigger and modulate the delivery of doxorubicin. The microparticles have been developed in four steps: (i) synthesis of the iron core; (ii) surface modification of the core; (iii) conjugation with the amphiphilic poly(lactic acid)-grafted chitosan; and (iv) doxorubicin loading. The particles demonstrate spherical shape, a size in the range of 1–3 µm and surface charge that is tuneable by changing the pH of the environment. The microparticles demonstrate good stability in simulated physiological solutions and are able to hold up to 400 µg of doxorubicin per mg of dried particles. The response to ultrasound and the changes in the shell structure during exposure to different pH levels allows the control of the burst intensity and release rate of the payload. Additionally, the magnetic response of the iron core is preserved despite the polymer coat. In vitro cytotoxicity tests performed on fibroblast NIH/3T3 demonstrate a reduction in the cell viability after administration of doxorubicin-loaded microparticles compared to the administration of free doxorubicin. The application of ultrasound causes a burst in the release of the doxorubicin from the carrier, causing a decrease in cell viability. The microparticles demonstrate in vitro cytocompatibility and hemocompatibility at concentrations of up to 50 and 60 µg/mL, respectively.

Author(s):  
Sergei Vlasov ◽  
Pavel Postnikov ◽  
Mikhail Belousov ◽  
Sergei Krivoshchekov ◽  
Mekhman Yusubov ◽  
...  

Hybrid microparticles based on an iron core and amphiphilic shell have been prepared to respond simultaneously to external (magnetic and ultrasounds field) and internal (pH) stimuli for delivery of the anticancer drug doxorubicin. The microparticles have been prepared in three main steps; including surface modification of the iron core followed by conjugation with the amphiphilic chitosan and drug loading. The particles demonstrate spherical shape and dimension in the range 1-3 m with tunable surface charge by changing the pH of surrounding environment. The microparticles demonstrate good stability in simulated physiological solutions and able to allocate up to 400 g of drug per mg of bare carrier. The response to ultrasound and the changes in the shell structure when exposed to different pH allows to control the doxorubicin release. In vitro cytotoxicity tests performed on fibloblast NIH/3T3 demonstrate a reduction in the cell viability when doxorubicin was administrated by microparticles compared to the free formulation; in particular when ultrasound were applied. The bare microparticles demonstrate cytocompatibility and hemocompatibility up to 50g/mL and 60 g/mL, respectively.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 127
Author(s):  
Bwalya A. Witika ◽  
Jessé-Clint Stander ◽  
Vincent J. Smith ◽  
Roderick B. Walker

Currently, the human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS) can only be treated successfully, using combination antiretroviral (ARV) therapy. Lamivudine (3TC) and zidovudine (AZT), two compounds used for the treatment of HIV and prevention of disease progression to AIDS are used in such combinations. Successful therapy with 3TC and AZT requires frequent dosing that may lead to reduced adherence, resistance and consequently treatment failure. Improved toxicity profiles of 3TC and AZT were observed when combined as a nano co-crystal (NCC). The use of stimuli-responsive delivery systems provides an opportunity to overcome the challenge of frequent dosing, by controlling and/or sustaining delivery of drugs. Preliminary studies undertaken to identify a suitable composition for a stimulus-responsive in situ forming hydrogel carrier for 3TC-AZT NCC were conducted, and the gelation and erosion time were determined. A 25% w/w Pluronic® F-127 thermoresponsive hydrogel was identified as a suitable carrier as it exhibited a gelation time of 5 min and an erosion time of 7 days. NCC-loaded hydrogels were evaluated using in vitro dissolution and cytotoxicity assays. In vitro dissolution undertaken using membrane-less diffusion over 168 h revealed that 3TC and AZT release from NCC-loaded hydrogels was complete and followed zero-order kinetic processes, whereas those loaded with the micro co-crystal and physical mixture were incomplete and best described using the Korsmeyer–Peppas kinetic model. The release of AZT and 3TC from the physical mixture and MCC-loaded gel exhibited a value for n of 0.595 for AZT release from the physical mixture and 0.540 for the MCC technology, whereas the release exponent for 3TC was 0.513 for the physical mixture and 0.557 for the MCC technology indicating that diffusion and erosion controlled 3TC and AZT release. In vitro cytotoxicity assay data revealed that the addition of NCC to the thermoresponsive hydrogel resulted in an improved cell viability of 88.0% ± 5.0% when compared to the cell viability of the NCC of 76.9% ± 5.0%. The results suggest that the use of a thermoresponsive nanosuspension may have the potential to be delivered as an intramuscular injection that can subsequently increase bioavailability and permit dose reduction and/or permit use of a longer dosing frequency.


2019 ◽  
Vol 13 (2) ◽  
pp. 114-128 ◽  
Author(s):  
Gayatri Patel ◽  
Bindu K.N. Yadav

Background: The purpose of this study was to formulate, characterize and conduct in vitro cytotoxicity of 5-fluorouracil loaded polymeric electrospun nanofibers for the treatment of skin cancer. The patents on electrospun nanofibers (US9393216B2), (US14146252), (WO2015003155A1) etc. helped in the selection of polymers and method for the preparation of nanofibers. Methods: In the present study, the fabrication of nanofibers was done using a blend of chitosan with polyvinyl alcohol and processed using the electrospinning technique. 5-fluorouracil with known chemotherapeutic potential in the treatment of skin cancer was used as a drug carrier. 24-1 fractional factorial screening design was employed to study the effect of independent variables like the concentration of the polymeric solution, applied voltage (kV), distance (cm), flow rate (ml / hr) on dependent variables like % entrapment efficiency and fiber diameter. Results: Scanning electron microscopy was used to characterize fiber diameter and morphology. Results showed that the fiber diameter of all batches was found in the range of 100-200 nm. The optimized batch results showed the fiber diameter of 162.7 nm with uniform fibers. The tensile strength obtained was 190±37 Mpa. Further in vitro and ex vivo drug release profile suggested a controlled release mechanism for an extended period of 24 hr. The 5-fluorouracil loaded electrospun nanofibers were found to decrease cell viability up to ≥50% over 24 hr, with the number of cells dropping by ~ 10% over 48 hr. As the cell viability was affected by the release of 5-fluorouracil, we believe that electrospun nanofibers are a promising drug delivery system for the treatment of Basal Cell Carcinoma (BCC) skin cancer. Conclusion: These results demonstrate the possibility of delivering 5-Fluorouracil loaded electrospun nanofiber to skin with enhanced encapsulation efficiency indicating the effectiveness of the formulation for the treatment of basal cell carcinoma type of skin cancer.


2012 ◽  
Vol 44 ◽  
pp. 866-868 ◽  
Author(s):  
A.P.S. Immich ◽  
M. Lis ◽  
L.H. Catalani ◽  
R.L. Boemo ◽  
J.A. Tornero

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1552
Author(s):  
Asmaa M. Abd El-Aziz ◽  
Azza El-Maghraby ◽  
Andrea Ewald ◽  
Sherif H. Kandil

Electrospun carbon nanofibers (CNFs), which were modified with hydroxyapatite, were fabricated to be used as a substrate for bone cell proliferation. The CNFs were derived from electrospun polyacrylonitrile (PAN) nanofibers after two steps of heat treatment: stabilization and carbonization. Carbon nanofibrous (CNF)/hydroxyapatite (HA) nanocomposites were prepared by two different methods; one of them being modification during electrospinning (CNF-8HA) and the second method being hydrothermal modification after carbonization (CNF-8HA; hydrothermally) to be used as a platform for bone tissue engineering. The biological investigations were performed using in-vitro cell counting, WST cell viability and cell morphology after three and seven days. L929 mouse fibroblasts were found to be more viable on the hydrothermally-modified CNF scaffolds than on the unmodified CNF scaffolds. The biological characterizations of the synthesized CNF/HA nanofibrous composites indicated higher capability of bone regeneration.


Author(s):  
Sherifat Banke Idris ◽  
Abdul Kadir Arifah ◽  
Faez Firdaus Abdullah Jesse ◽  
Siti Zubaidah Ramanoon ◽  
Muhammad Abdul Basit ◽  
...  

Background: Evaluation of the toxic effects of nanoparticle-drug in vitro is an important step in the design of new pharmaceutical formulations. Rapid results, reduced cost and easy handling makes cell culture models first line in initial toxicological assessment of nanodrug preparations. Objective: To evaluate the in vitro cytotoxicity of oxytetracycline loaded calcium carbonate aragonite nanoparticle in normal mouse fibroblast (NIH3T3) cell line. Method: NIH3T3 cells were exposed to varying concentrations (6.25 - 100µg/mL) of calcium carbonate aragonite nanoparticle (CS-CaCO3NP), oxytetracycline loaded calcium carbonate aragonite nanoparticle (OTC-CS-CaCO3NP) and oxytetracycline (OTC) in 96 well plates for 24, 48 and 72 hours. Cell viability was determined by MTT and trypan blue assays. Result: Both assays show that CS-CaCO3NP and OTC-CS-CaCO3NP had higher cell viability values compared to OTC. Conclusion: Encapsulating OTC into CS-CaCO3NP reduced its cytotoxicity to NIH3T3 cells using both MTT and trypan blue assay.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 7598-7598 ◽  
Author(s):  
R. Blumenthal ◽  
R. Stein ◽  
R. Michell ◽  
D. M. Goldenberg

7598 Background: The internalizing LL1 anti-CD74 antibody is an optimal agent for delivering drugs, toxins, or radionuclides to CD74+ cancer cells. Here, we investigated the efficacy of IMMU-110 (Immunomedics, Inc.) in common follicular and aggressive types of NHL cells and in two disseminated non-Burkitt NHL models. Methods: CD74, MDR and MRP expression on NHL cell lines was determined by flow cytometry. In vitro cytotoxicity was assessed by cell cycle analysis of propidium iodide (PI)-stained cells and by measuring apoptotic cells using FITC-Annexin V and PI. In vivo therapy of a single 350-μg dose of IMMU-110 was evaluated in disseminated SUDHL4 and FSCCL. Results: Raji and Daudi Burkitt lines express similar amounts of CD74 (>93% positive cells and a MCF=35), yet a 3-day treatment with 0.8 μg/ml of IMMU-110 results is 18.4% of Raji and 67.9% of Daudi cells in Sub-Go. Aside from Daudi cells that respond with cells shifting into Sub-Go, most other NHL cell lines experience a G2/M block (44%-82% of cells) in response to a 3-day exposure to IMMU-110. Both MDR- and MDR+ NHL cells responded to IMMU-110. Kaplan Meier analysis showed a significant increase in survival of both SUDHL4 (MDR-/MRP-)- and FSCCL (MDR+/MRP+)-bearing SCID mice (P < 0.025) with 100% survival of treated mice vs. 38% survival of untreated mice at 70–77 days post cell implantation. Conclusions: IMMU-110 is cytotoxic in non-Burkitt and in Burkitt NHL cell lines. The magnitude of the cytotoxic response is not related to the amount of CD74 expressed on the cell surface. IMMU-110 is therapeutic in drug-sensitive (SUDHL4) and drug-resistant (FSCCL) NHL models, suggesting that antibody targeting can bypass the MDR drug efflux system that prevents free doxorubicin from being therapeutic. [Table: see text] [Table: see text]


2021 ◽  
Vol 323 ◽  
pp. 146-151
Author(s):  
Khishigdemberel Ikhbayar ◽  
Nomin Myagmar ◽  
Gantulga Davaakhuu ◽  
Uyanga Enkhnaran ◽  
Enkhmend Bekhbaatar ◽  
...  

Magnetic nanoparticles for thermotherapy must be biocompatible and possess high thermal efficiency as heating elements. The biocompatibility of Mg 0.8 Ni 0.2 Fe 2 O 4 nanoparticles was studied using a cytotoxicity colony formation assay and a cell viability assay. HeLa cells exhibited cytotoxic effects when exposed to three different concentrations of 150 μg /ml, 100 μg /ml, and 50 μg /ml nanoparticles. Therefor e, c oncentrations of 50 μg /ml showed the lowest cytotoxic activity and the lowest toxicity to living cells. In vitro cytotoxicity of samples was then investigated by two methods, colony formation assay and cell viability assay. The Hela inhibited cell growth as 16.8% during heating by magnetic field generators.


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