scholarly journals Cellular Uptake and Intracellular Cargo Release From Dextran Based Nanogel Drug Carriers

Author(s):  
M. Carme Coll Ferrer ◽  
Peter Sobolewski ◽  
Russell J. Composto ◽  
David M. Eckmann

Nanogels (NG) hold great promise as a drug delivery platform. In this work, we examine the potential of lysozyme-dextran nanogels (LDNG) as drug carriers in vitro using two cell lines: a model target tissue, human umbilical cord vein endothelial cells (HUVEC) and a model of the mononuclear phagocyte system (phorbol 12-myristate 13-acetate (PMA)-stimulated THP-1 cells). The LDNG (∼100 nm) were prepared with rhodamine-label dextran (LRDNG) via Maillard reaction followed by heat-gelation reaction and were loaded with a fluorescent probe, 5-hexadecanoylaminofluorescein (HAF), as a mock drug. Epifluorescence microscopy confirmed rapid uptake of LRDNG by HUVEC. Although LysoTracker Green staining indicated a lysosomal fate for LRDNG, the mock drug cargo (HAF) diffused extensively inside the cell within 15 min. Flow cytometry and confocal microscopy indicated slow uptake of LRDNG in PMA-stimulated THP-1 cells, with only 41% of cells containing LRDNG after 24 h exposure. Finally, 24 h exposure to LRDNG did not affect the viability of either cell type at the dose studied (20 μg/ml). At a higher dose (200 μg/ml), LRDNG resulted in a marked loss of viability of HUVEC and THP-1, measuring 30% and 38%, respectively. Collectively, our results demonstrate the great potential of LRDNG as a drug delivery platform, combining simple production, rapid uptake and cargo release in target cells with “stealth” properties and low cytotoxicity.

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S279-S294 ◽  
Author(s):  
Paul Robel

ABSTRACT Of the information available on steroid hormone metabolism in responsive tissues, only that relating hormone metabolism to physiological activity is reviewed, i. e. metabolite activity in isolated in vitro systems, binding of metabolites to target tissue receptors, specific steroid hormone metabolizing enzymes and relationship of hormone metabolism to target organ physiological state. Further, evidence is presented in the androgen field, demonstrating 5α-reduced metabolites, formed inside the target cells, as active compounds. This has led to a consideration of testosterone as a »prehormone«. The possibility that similar events take place in tissues responding to progesterone is discussed. Finally, the role of hormone metabolism in the regulation of hormone availability and/or renewal in target cells is discussed. In this context, reference is made to the potential role of plasma binding proteins and cytosol receptors.


2021 ◽  
Author(s):  
Moataz Dowaidar

Gene therapy involves transferring genetic material (DNA or RNA) to repair, regulate or replace genes to cure a disease. One of the most crucial barriers is successful delivery of the targeted gene into the target tissue. Various vector-based approaches have been developed to deliver the transgene to the target cells. In different cancers, numerous of these vectors are being developed for purposes such as immunotherapy, suicide gene therapy, microRNA (miRNA) focused treatment, oncogene silencing, and gene editing using CRISPR/Cas9. This article reviews several alternatives to cancer gene therapy, as well as their preclinical and clinical outcomes, possible limitations, and overall therapy effects. Ways of delivering cancer gene therapy include direct methods for introducing genetic material. Nonviral vectors are easy to manufacture and may be chemically modified to increase their usefulness. Cationic polymers such as Poly-L-Lysine (PLL) and Polyethylenimine (PEI-SS) are the most extensively used polycationic polymers for gene transfer, particularly in vitro. Many RNAi-based therapeutic approaches are approaching the clinical stage, and nanocarriers are likely to play a crucial role in treating specific cancers. In the previous decade, non-viral approaches were used in more than 17 percent of all gene therapy trials. The message is that this is a safe and effective technique for transferring genes to cancer patients who need it to be a safe, successful therapy. Exosomes were developed to carry oncogene-specific short interfering RNA. Sushrut and colleagues revealed that exosomes provide superior carriers of short RNA and prevent tumor growth than liposomes. Inhalation-based gene therapy (aerosol-mediated gene delivery) has gained pace as a feasible treatment approach, especially for lung cancer. Because the intended transgene is steered to specific cells/tissues, this should further increase therapeutic efficiency.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Mohsin Khan ◽  
Suresh K Verma ◽  
Alexander R Mackie ◽  
Erin Vaughan ◽  
Srikanth Garikipati ◽  
...  

Rationale: Embryonic stem cells (ESCs) hold great promise for cardiac regeneration but are susceptible to ethical concerns, lack of autologous donors and teratoma formation. Recently, it has been observed that beneficial effects of stem cells are mediated by exosomes secreted out under various physiological conditions. ESCs have the ability to produce exosomes however their effect in the context of the heart is unknown. Objective: Determine the effect of ESC derived exosomes for cardiac repair and modulation of CPCs functions in the heart following myocardial infarction. Methods and Results: Exosomes were isolated from murine ESCs (mES Ex) or embryonic fibroblasts (MEFs) by ultracentrifugation and verified by Flotillin-1 immunoblot analysis. Induction of pluripotent markers, survival and in vitro tube formation was enhanced in target cells receiving ESC exosomes indicating therapeutic potential of mES Ex. mES Ex administration resulted in enhanced neovascularization, cardiomyocyte survival and reduced fibrosis post infarction consistent with resurgence of cardiac proliferative response. Importantly, mES Ex mediated considerable enhancement of cardiac progenitor cell (CPC) survival, proliferation and cardiac commitment concurrent with increased c-kit+ CPCs in vivo 4 weeks after mES Ex transfer. miRNA Array analysis of ESC and MEF exosomes revealed significantly high expression of miR290-295 cluster in the ESC exosomes compared to MEF exosomes. The underlying beneficial effect of mES Ex was tied to delivery of ESC miR-294 to the heart and in particular CPCs thereby promoting CPC survival and proliferation as analyzed by FACS based cell death analysis and CyQuant assay respectively. Interestingly, enhanced G1/S transition was observed in CPCs treated with miR-294 in conjunction with significant reduction of G1 phase. Conclusion: In conclusion, mES Ex provide a novel cell free system for cardiac regeneration with the ability to modulate both cardiomyocyte and CPC based repair programs in the heart thereby avoiding the risk of teratoma formation associated with ESCs.


Cartilage ◽  
2020 ◽  
pp. 194760352095939
Author(s):  
Sarah E. Mailhiot ◽  
Matthew A. Thompson ◽  
Akiko E. Eguchi ◽  
Sabrina E. Dinkel ◽  
Martin K. Lotz ◽  
...  

Objective Intra-articular drug delivery holds great promise for the treatment of joint diseases such as osteoarthritis. The objective of this study was to evaluate the TAT peptide transduction domain (TAT-PTD) as a potential intra-articular drug delivery technology for synovial joints. Design Experiments examined the ability of TAT conjugates to associate with primary chondrocytes and alter cellular function both in vitro and in vivo. Further experiments examined the ability of the TAT-PTD to bind to human osteoarthritic cartilage. Results The results show that the TAT-PTD associates with chondrocytes, is capable of delivering siRNA for chondrocyte gene knockdown, and that the recombinant enzyme TAT-Cre is capable of inducing in vivo genetic recombination within the knee joint in a reporter mouse model. Last, binding studies show that osteoarthritic cartilage preferentially uptakes the TAT-PTD from solution. Conclusions The results suggest that the TAT-PTD is a promising delivery strategy for intra-articular therapeutics.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Ting-Ting Yang ◽  
Yuan-Zheng Cheng ◽  
Meng Qin ◽  
Yong-Hong Wang ◽  
Hong-Li Yu ◽  
...  

Thermosensitive hydrogels have increasingly received considerable attention for local drug delivery based on many advantages. However, burst release of drugs is becoming a critical challenge when the hydrogels are employed. Microspheres- (MS-) loaded thermosensitive hydrogels were thus fabricated to address this limitation. Employing an orthogonal design, the spray-dried operations of tenofovir (TFV)/Bletilla striata polysaccharide (BSP)/chitosan (CTS) MS were optimized according to the drug loading (DL). The physicochemical properties of the optimal MS (MS F) were characterized. Depending on the gelation temperature and gelating time, the optimal CTS-sodium alginate- (SA-) α,β-glycerophosphate (GP) (CTS-SA-GP) hydrogel was obtained. Observed by scanning electron microscope (SEM), TFV/BSP/CTS MS were successfully encapsulated in CTS-SA-GP. In vitro releasing demonstrated that MS F-CTS-SA-GP retained desirable in vitro sustained-release characteristics as a vaginal delivery system. Bioadhesion measurement showed that MS-CTS-SA-GP exhibited the highest mucoadhesive strength. Collectively, MS-CTS-SA-GP holds great promise for topical applications as a sustained-release vaginal drug delivery system.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Jonathan Rios-Doria ◽  
Adam Carie ◽  
Tara Costich ◽  
Brian Burke ◽  
Habib Skaff ◽  
...  

Chemotherapeutic drugs are widely used for the treatment of cancer; however, use of these drugs is often associated with patient toxicity and poor tumor delivery. Micellar drug carriers offer a promising approach for formulating and achieving improved delivery of hydrophobic chemotherapeutic drugs; however, conventional micelles do not have long-term stability in complex biological environments such as plasma. To address this problem, a novel triblock copolymer has been developed to encapsulate several different hydrophobic drugs into stable polymer micelles. These micelles have been engineered to be stable at low concentrations even in complex biological fluids, and to release cargo in response to low pH environments, such as in the tumor microenvironment or in tumor cell endosomes. The particle sizes of drugs encapsulated ranged between 30–80 nm, with no relationship to the hydrophobicity of the drug. Stabilization of the micelles below the critical micelle concentration was demonstrated using a pH-reversible crosslinking mechanism, with proof-of-concept demonstrated in both in vitro and in vivo models. Described herein is polymer micelle drug delivery system that enables encapsulation and stabilization of a wide variety of chemotherapeutic drugs in a single platform.


Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 640 ◽  
Author(s):  
Jihye Yoo ◽  
Changhee Park ◽  
Gawon Yi ◽  
Donghyun Lee ◽  
Heebeom Koo

Targeting nanoparticle (NP) carriers to sites of disease is critical for their successful use as drug delivery systems. Along with optimization of physicochemical properties, researchers have focused on surface modification of NPs with biological ligands. Such ligands can bind specific receptors on the surface of target cells. Furthermore, biological ligands can facilitate uptake of modified NPs, which is referred to as ‘active targeting’ of NPs. In this review, we discuss recent applications of biological ligands including proteins, polysaccharides, aptamers, peptides, and small molecules for NP-mediated drug delivery. We prioritized studies that have demonstrated targeting in animals over in vitro studies. We expect that this review will assist biomedical researchers working with NPs for drug delivery and imaging.


2005 ◽  
Vol 288-289 ◽  
pp. 129-132 ◽  
Author(s):  
Ling Chen ◽  
Xiao Xi Li ◽  
Lin Li ◽  
Bing Li

Colon-targeting drug delivery systems (CDDSs) are employed to improve the bioavailability of protein and peptide drugs through the oral route. So it is important to prepare the drug carriers for oral CDDS. In this study, the Enzyme-Resistant starch (RS) was studied for use as a vehicle in oral colon-targeting drug delivery. The characteristics of RS powders were investigated by X-ray diffraction, polarizing microscopy, DSC and SEM, and their film were examined by enzymatic digestion test. The results showed that RS could be a promising film-former for pharmaceutical coatings, having good stability to enzymatic digestion. Furthermore, a novel peroral formulation using RS coating and bovine serum albumin as a model drug was studied for colon-specific drug delivery in vitro. Drug release studies have shown that RS coating could delivery the drug to the colon and the release rate in simulated colonic fluids was dependent on the biodegradation of RS and its coatings. It is indicated that the RS coated tablet is a potential system for oral CDDS.


2020 ◽  
Author(s):  
Andrew Tae-Jun Kwon ◽  
Kohta Mohri ◽  
Satoshi Takizawa ◽  
Takahiro Arakawa ◽  
Maiko Takahashi ◽  
...  

AbstractAntibody-drug conjugates offers many advantages as a drug delivery platform that allows for highly specific targeting of cell types and genes. Ideally, testing the efficacy of these systems requires two cell types to be different only in the gene targeted by the drug, with the rest of the cellular machinery unchanged, in order to minimize other potential differences from obscuring the effects of the drug. In this study, we created multiple variants of U87MG cells with targeted mutation in the TP53 gene using the CRISPR-Cas9 system, and determined that their major transcriptional differences stem from the loss of p53 function. Using the transcriptome data, we predicted which mutant clones would have less divergent phenotypes from the wild type and thereby serve as the best candidates to be used as drug delivery testing platforms. Further in vitro and in vivo assays of cell morphology, proliferation rate and target antigen-mediated uptake supported our predictions. Based on the combined analysis results, we successfully selected the best qualifying mutant clone. This study serves as proof-of-principle of the approach and paves the way for extending to additional cell types and target genes.


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