scholarly journals Three-Step Synthesis of a Redox-Responsive Blend of PEG–block–PLA and PLA and Application to the Nanoencapsulation of Retinol

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2350
Author(s):  
Louise Van Gheluwe ◽  
Eric Buchy ◽  
Igor Chourpa ◽  
Emilie Munnier

Smart polymeric nanocarriers have been developed to deliver therapeutic agents directly to the intended site of action, with superior efficacy. Herein, a mixture of poly(lactide) (PLA) and redox-responsive poly(ethylene glycol)–block–poly(lactide) (PEG–block–PLA) containing a disulfide bond was synthesized in three steps. The nanoprecipitation method was used to prepare an aqueous suspension of polymeric nanocarriers with a hydrodynamic diameter close to 100 nm. Retinol, an anti-aging agent very common in cosmetics, was loaded into these smart nanocarriers as a model to measure their capacity to encapsulate and to protect a lipophilic active molecule. Retinol was encapsulated with a high efficiency with final loading close to 10% w/w. The stimuli-responsive behavior of these nanocarriers was demonstrated in vitro, in the presence of l-Glutathione, susceptible to break of disulfide bond. The toxicity was low on human keratinocytes in vitro and was mainly related to the active molecule. Those results show that it is not necessary to use 100% of smart copolymer in a nanosystem to obtain a triggered release of their content.

2018 ◽  
Vol 24 (28) ◽  
pp. 3303-3319 ◽  
Author(s):  
Erfaneh Ghassami ◽  
Jaleh Varshosaz ◽  
Somayeh Taymouri

Background: Among the numerous bio-responsive polymeric drug delivery systems developed recently, redox-triggered release of molecular payloads have gained great deal of attention, especially in the field of anticancer drug delivery. In most cases, these systems rely on disulfide bonds located either in the matrix crosslinks, or in auxiliary chains to achieve stimuli-responsive drug release. These bonds keep their stability in extracellular environments, yet, rapidly break by thiol–disulfide exchange reactions in the cytosol, due to the presence of greater levels of glutathione. Polysaccharides are macromolecules with low cost, natural abundance, biocompatibility, biodegradability, appropriate physical and chemical properties, and presence of numerous functional groups which facilitate chemical or physical cross-linking. Methods: With regards to the remarkable advantages of polysaccharides, in the current study, various polysaccharide-based redox-responsive drug delivery systems are reviewed. In most cases the in vitro/in vivo effects of the developed system were also evaluated. Results: Considering the hypoxic and reducing nature of the tumor microenvironment, with several folds higher glutathione levels than the systemic tissues, redox-sensitive polymeric systems could be implemented for tumorspecific drug delivery and the results of the previous researches in this field indicated satisfactory achievements. Conclusion: According to the reviewed papers, the efficiency of diverse redox-responsive polysaccharide-based nanoparticles with therapeutic payloads in cancer chemotherapy could be concluded. Nevertheless, more comprehensive studies are required to understand the exact intracellular and systemic fate of these nano-carriers, as well as their clinical efficacy for cancer treatment.


2021 ◽  
Vol 9 ◽  
Author(s):  
Man Zhou ◽  
Yan Luo ◽  
Weijia Zeng ◽  
Xiaoqing Yang ◽  
Tingting Chen ◽  
...  

Chemotherapy is one of the commonly used therapies for the treatment of malignant tumors. Insufficient drug-loading capacity is the major challenge for polymeric micelle–based drug delivery systems of chemotherapy. Here, the redox-responsive star-shaped polymeric prodrug (PSSP) and the dimeric prodrug of paclitaxel (PTX) were prepared. Then the dimeric prodrug of PTX (diPTX, diP) was loaded into the core of the star-shaped polymeric prodrug micelles of PSSP by hydrophobic interaction forming the redox-responsive prodrug micelles of diPTX@PSSP for intracellular drug release in tumor cells. The hydrodynamic diameter of diPTX@PSSP nanoparticles was 114.3 nm ± 2.1 (PDI = 0.219 ± 0.016), and the micelles had long-term colloidal stability and the drug-loading content (DLC) of diPTX and PTX is 16.7 and 46.9%, respectively. The prepared micelles could broke under the reductive microenvironment within tumor cells, as a result, the dimeric prodrug of diP and polymeric prodrug micelles of PSSP were rapidly disassembled, leading to the rapid release of intracellular drugs. In vitro release studies showed that under the condition of reduced glutathione (GSH) (10 mM), the release of PTX was significantly accelerated with approximately 86.6% released within 21 h, and the released PTX in cytoplasm could promote the disintegration of microtubules and induce cell apoptosis. These results indicated that the new type of this reduction-sensitive nanodrug delivery system based on dimeric prodrug@polymeric prodrug micelles would be a promising technology in chemotherapy.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Tyler Brann ◽  
Dhruvinkumar Patel ◽  
Rajat Chauhan ◽  
Kurtis T. James ◽  
Paula J. Bates ◽  
...  

The selective exposure of cancerous tissue to systemically delivered chemotherapeutic agents remains a major challenge facing cancer therapy. To address this question, a near infrared responsive oligonucleotide-coated (AS1411, hairpin, or both) gold nanoplate loaded with doxorubicin is demonstrated to be nontoxic to cells without triggered release, while being acutely toxic to cells after 5 minutes of laser exposure to trigger DOX release. Conjugation of oligonucleotides to the nanoplates is confirmed by an average increase in hydrodynamic diameter of 30.6 nm, an average blue shift of the plasmon resonance peak by 36 nm, and an average −10 mV shift in zeta potential of the particles. DOX loading through intercalation into the hairpin DNA structure is confirmed through fluorescence measurements. For both GNP-Hairpin and GNP-Hairpin-AS1411, ~60% of loaded DOX is released after the first 5 minutes of laser exposure (λ=817 nm), with complete release after two more 5-minute exposures. Preliminary proof of concept is demonstrated in vitro using A549 and MDA-MB-231 cell lines as models for breast and lung cancer, respectively. Exposure of cells to untriggered DOX-loaded conjugate with no laser exposure results in little to no toxicity, while laser-triggered release of DOX causes significant cell death.


2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Ziting Cheng ◽  
Wei Zhang ◽  
Xiaoya Hou ◽  
Bingjie Wang ◽  
Yanping Zhu ◽  
...  

AbstractIn this paper, a type of phycocyanin (PC)-functionalized and curcumin (CUR)-loaded biotin-chitosan oligosaccharide-dithiodipropionic acid-curcumin (BCSC) nanoparticles, called CUR-BCSC@PCs, were designed to enhance the biocompatibility of CUR. The structure of BCSC was confirmed using 1H-NMR. In CUR-BCSC@PCs with an average hydrodynamic diameter of 160.3 ± 9.0 nm, the biomimetic protein corona gave the nanoparticles excellent stability and the potential to avoid protein adsorption in blood circulation. The in vitro release experiment verified that CUR-BCSC@PCs with redox responsive shells were sensitive to high concentrations of glutathione. In addition, CUR-BCSC@PCs were effective at increasing the inhibitory activity on the proliferation of A549 cells by enhancing the intracellular uptake of CUR. These results indicated that CUR-BCSC@PCs have great application prospects in cancer therapy as effective drug delivery carriers.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1514
Author(s):  
Jéssica A. Magalhães ◽  
Denise C. Arruda ◽  
Maurício S. Baptista ◽  
Dayane B. Tada

The development of resistance against photodamage triggered by photodynamic therapy (PDT) is ascribed mainly to the cellular redox defenses and repair. If the tumor tissue is not promptly eliminated by the first few PDT sessions, PDT-resistance can be favored, challenging the efficacy of the treatment. Although the mechanism of PDT resistance is still unclear, in vitro assays have evidenced that it can be developed through the PARP damage-repair signaling pathway. Therefore, inhibition of poly(adenosine diphosphate (ADP)-ribose) polymerase (PARP) has the potential to increase PDT efficacy. This work reports on the synthesis of a controlled release system of a photosensitizer, methylene blue (MB) and a PARP-inhibitor, the veliparib. MB and veliparib were co-encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (VMB-NPs). A colloidal stable aqueous suspension of nanoparticles was obtained. The average hydrodynamic diameter was 90 nm and a narrow size distribution was obtained, with a polydispersity index (PDI) of 0.08. The release kinetics of MB and veliparib from VMB-NPs showed an initial burst of 8.7% and 58.3% release of the total amounts of MB and veliparib respectively, in the first 6 h, and a delayed release of up to 11.3% and 70%, in 19 days, for MB and veliparib, respectively. The VMB-NPs showed no cytotoxicity in the dark but the viability of B16F10-Nex2 cells decreased by 36% when the cells were irradiated (102 J/cm2, 660 nm) and treated with VMB-NPs containing 1.0 µM of MB and 8.3 µM of veliparib. Considering the increased photoactivity even at low MB and veliparib concentrations and the absence of cytotoxicity in dark, the co-encapsulation of MB and veliparib was shown to be a promising strategy to improve the PDT efficacy.


Author(s):  
A. R. Crooker ◽  
M. C. Myers ◽  
T. L. Beard ◽  
E. S. Graham

Cell culture systems have become increasingly popular as a means of screening toxic agents and studying toxic mechanisms of drugs and other chemicals at the cellular and subcellular levels. These in vitro tests can be conducted rapidly in a broad range of relevant mammalian culture systems; a variety of biological and biochemical cytotoxicity endpoints can be examined. The following study utilized human keratinocytes to evaluate the relative cytotoxicities of nitrofurazone (NF) and silver sulfadiazine (SS), the active ingredients of FURACIN(R) Topical Cream and SILVADENE(R) Cream, respectively. These compounds are anti-infectives used in the treatment of burn patients. Cell ultrastructure and elemental composition were utilized as cytotoxicity endpoints.Normal Human Epidermal Keratinocytes (HK) were prepared from the EpiPackTM culture system (Clonetics Corporation, Boulder, CO). For scanning electron microscopy (SEM) and transmission electron microscopy (TEM), cells were seeded on sterile 35 mm Falcon plastic dishes; for elemental microanalysis, cells were plated on polished pyrolytic carbon discs (E. Fullam, Latham, NY) placed in the culture dishes.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 533
Author(s):  
Eloy Pena-Rodríguez ◽  
Maria Lajarin-Reinares ◽  
Aida Mata-Ventosa ◽  
Sandra Pérez-Torras ◽  
Francisco Fernández-Campos

Follicular targeting has gained more attention in recent decades, due to the possibility of obtaining a depot effect in topical administration and its potential as a tool to treat hair follicle-related diseases. Lipid core ethyl cellulose lipomers were developed and optimized, following which characterization of their physicochemical properties was carried out. Dexamethasone was encapsulated in the lipomers (size, 115 nm; polydispersity, 0.24; zeta-potential (Z-potential), +30 mV) and their in vitro release profiles against dexamethasone in solution were investigated by vertical diffusion Franz cells. The skin biodistribution of the fluorescent-loaded lipomers was observed using confocal microscopy, demonstrating the accumulation of both lipomers and fluorochromes in the hair follicles of pig skin. To confirm this fact, immunofluorescence of the dexamethasone-loaded lipomers was carried out in pig hair follicles. The anti-inflammatory (via TNFα) efficacy of the dexamethasone-loaded lipomers was demonstrated in vitro in an HEK001 human keratinocytes cell culture and the in vitro cytotoxicity of the nanoformulation was investigated.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasaman Shamshirgaran ◽  
Anna Jonebring ◽  
Anna Svensson ◽  
Isabelle Leefa ◽  
Mohammad Bohlooly-Y ◽  
...  

AbstractRecent advances in induced pluripotent stem cells (iPSCs), genome editing technologies and 3D organoid model systems highlight opportunities to develop new in vitro human disease models to serve drug discovery programs. An ideal disease model would accurately recapitulate the relevant disease phenotype and provide a scalable platform for drug and genetic screening studies. Kidney organoids offer a high cellular complexity that may provide greater insights than conventional single-cell type cell culture models. However, genetic manipulation of the kidney organoids requires prior generation of genetically modified clonal lines, which is a time and labor consuming procedure. Here, we present a methodology for direct differentiation of the CRISPR-targeted cell pools, using a doxycycline-inducible Cas9 expressing hiPSC line for high efficiency editing to eliminate the laborious clonal line generation steps. We demonstrate the versatile use of genetically engineered kidney organoids by targeting the autosomal dominant polycystic kidney disease (ADPKD) genes: PKD1 and PKD2. Direct differentiation of the respective knockout pool populations into kidney organoids resulted in the formation of cyst-like structures in the tubular compartment. Our findings demonstrated that we can achieve > 80% editing efficiency in the iPSC pool population which resulted in a reliable 3D organoid model of ADPKD. The described methodology may provide a platform for rapid target validation in the context of disease modeling.


Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 768
Author(s):  
Maddalena Sguizzato ◽  
Francesca Ferrara ◽  
Supandeep Singh Hallan ◽  
Anna Baldisserotto ◽  
Markus Drechsler ◽  
...  

Mangiferin is a natural glucosyl xanthone with antioxidant and anti-inflammatory activity, making it suitable for protection against cutaneous diseases. In this study ethosomes and transethosomes were designed as topical delivery systems for mangiferin. A preformulation study was conducted using different surfactants in association with phosphatidylcholine. Vesicle dimensional distribution was monitored by photon correlation spectroscopy, while antioxidant capacity and cytotoxicity were respectively assessed by free radical scavenging analysis and MTT on HaCaT keratinocytes. Selected nanosystems were further investigated by cryogenic transmission electron microscopy, while mangiferin entrapment capacity was evaluated by ultracentrifugation and HPLC. The diffusion kinetics of mangiferin from ethosomes and transethosomes evaluated by Franz cell was faster in the case of transethosomes. The suitability of mangiferin-containing nanovesicles in the treatment of skin disorders related to pollutants was investigated, evaluating, in vitro, the antioxidant and anti-inflammatory effect of ethosomes and transethosomes on human keratinocytes exposed to cigarette smoke as an oxidative and inflammatory challenger. The ability to induce an antioxidant response (HO-1) and anti-inflammatory status (IL-6 and NF-kB) was determined by RT-PCR and immunofluorescence. The data demonstrated the effectiveness of mangiferin loaded in nanosystems to protect cells from damage. Finally, to gain insight into the keratinocytes’ uptake of ethosome and transethosome, transmission electron microscopy analyses were conducted, showing that both nanosystems were able to pass intact within the cells.


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