An investigation of nano- and micron-sized carriers based on calcium carbonate and polylactic acid for oral administration of siRNA.

BACKGROUND: Oral delivery of small interfering RNAs (siRNAs) draws significant attention, but the gastrointestinal tract (GIT) has many biological barriers that limit the drugs' bioavailability. The aim of this work was to investigate the potential of micro- and nano-sized CaCO3 and PLA carriers for oral delivery of siRNA and reveal a relationship between the physicochemical features of these carriers and their biodistribution. RESEARCH DESIGN AND METHODS: In vitro stability of carriers was investigated in simulated gastric and intestinal fluids. Toxicity and cellular uptake were investigated on Caco-2 cells. The biodistribution profiles of the developed CaCO3 and PLA carriers were examined using different visualization methods, including SPECT, fluorescence imaging, radiometry, and histological analysis. The delivery efficiency of siRNA loaded carriers was investigated both in vitro and in vivo. RESULTS: Micro-sized carriers were accumulated in the stomach and later localized in the colon tissues. The nanoscale particles (100-250 nm) were distributed in the colon tissues. nPLA was also detected in small intestine. The developed carriers can prevent siRNA from premature degradation in GIT media. CONCLUSION: Our results reveal how the physicochemical properties of the particles, including their size and material type can affect their biodistribution profile and oral delivery of siRNA.

Design and one-pot synthesis of new substituted pyrrolo[1,2-a]thieno[3,2-e]pyrimidine as potential antitumor agents: in vitro and in vivo studies.

A new efficient and versatile one-pot three-component synthesis of substituted pyrrolo[1,2-a]thieno[3,2-e]pyrimidine derivatives has been developed. It is based on a multistep cascade reaction from 2-aminothiophenes and 2-hydroxy-4-oxobut-2-enoic acids, and derivatives of cyanoacetic acid catalyzed by diisopropylethylamine. As a result, novel pyrrolo[1,2-a]thieno[3,2-e]pyrimidine derivatives (21 compounds) were synthesized in a mild reaction conditions with a high yield. The structures of the developed compounds were confirmed by NMR and elemental analysis. The influence of electron-withdrawing or electron-donor substituents on the antitumor activity of the developed compounds has been identified. In vitro screening analysis of 21 compounds revealed six lead candidates (12aa, 12dc, 12hc, 12ic, 12lb, and 12mb) that demonstrated the most significant antitumor activity against B16-F10, 4T1 and CT26 cells. Necrosis/apoptosis assay showed that apoptosis was the predominant mechanism of cell death. Molecular docking analysis revealed several potential targets for tested compounds, i.e. phosphatidylinositol 5-phosphate 4-kinase (PI5P4K2C), proto-oncogene serine/threonine-protein kinase (Pim-1), nicotinamide phosphoribosyltransferase (NAMPT) and dihydrofolate reductase (DHFR). The lead compound (12aa) can effectively induce cell apoptosis, possesses a high yield (98 %) and requires low-cost starting chemicals for its synthesis. In vivo experiments with melanoma-bearing mice confirmed that 12aa compound resulted in the significant tumor inhibition on 15 d after the therapy. In particular, tumor volume was ∼0.19 cm3 for 50 mg/kg versus ∼2.39 cm3 in case of untreated mice and tumor weight was ∼71.6 mg for 50 mg/kg versus ∼452.4 mg when considered untreated mice. Thus, our results demonstrated the high potential of the 12aa compound in the treatment of melanoma and can be recommended for further preclinical studies.

Labeling and Tracking of Individual Human Mesenchymal Stromal Cells Using Photoconvertible Fluorescent Microcapsules.

The behavior and migration of human mesenchymal stromal cells (hMSCs) are focal points of research in the biomedical field. One of the major aspects is potential therapy using hMCS, but at present, the safety of their use is still controversial owing to limited data on changes that occur with hMSCs in the long term. Fluorescent photoconvertible proteins are intensively used today as "gold standard" to mark the individual cells and study single-cell interactions, migration processes, and the formation of pure lines. A crucial disadvantage of this method is the need for genetic modification of the primary culture, which casts doubt on the possibility of exploring the resulting clones in personalized medicine. Here we present a new approach for labeling and tracking hMSCs without genetic modification based on the application of cell-internalizable photoconvertible polyelectrolyte microcapsules (size: 2.6 ± 0.5 µm). These capsules were loaded with rhodamine B, and after thermal treatment, exhibited fluorescent photoconversion properties. Photoconvertible capsules demonstrated low cytotoxicity, did not affect the immunophenotype of the hMSCs, and maintained a high level of fluorescent signal for at least seven days. The developed approach was tested for cell tracking for four days and made it possible to trace the destiny of daughter cells without the need for additional labeling.

N-[4-(N,N,N-Trimethylammonium)Benzyl]Chitosan Chloride as a Gene Carrier: The Influence of Polyplex Composition and Cell Type.

Polyplex-based gene delivery systems are promising substitutes for viral vectors because of their high versatility and lack of disadvantages commonly encountered with viruses. In this work, we studied the DNA polyplexes with N-[4-(N,N,N-trimethylammonium)benzyl]chitosan chloride (TMAB-CS) of various compositions in different cell types. Investigations of the interaction of TMAB-CS with DNA by different physical methods revealed that the molecular weight and the degree of substitution do not dramatically influence the hydrodynamic properties of polyplexes. Highly substituted TMAB-CS samples had a high affinity for DNA. The transfection protocol was optimized in HEK293T cells and achieved the highest efficiency of 30-35%. TMAB-CS was dramatically less effective in nonadherent K562 cells (around 1% transfected cells), but it was more effective and less toxic than polyarginine.

High prevalence of CD3, NK, and NKT cells in the graft predicts adverse outcome after matched-related and unrelated transplantations with post transplantation cyclophosphamide.

The predictive value of graft composition and plasma biomarkers on the outcome of allogeneic HSCT is well known for conventional GVHD prophylaxis based on calcineurin inhibitors with or without antithymocyte globulin. Currently, there is limited data whether these results could be translated to post transplantation cyclophosphamide (PTCy). The prospective extension cohort of NCT02294552 trial enrolled 79 adult patients with acute leukemia in CR. Twenty-six received matched-related bone marrow (BM) grafts with single-agent PTCy and 53 received unrelated peripheral blood stem cell graft (PBSC) with PTCy, tacrolimus, and MMF. The grafts were studied by the flow cytometry, and plasma samples were analyzed by ELISA. In the cluster and major component analysis, we determined that transplantation from donors with high content of CD3, NKT, and CD16-CD56 + subpopulations in the PBSC grafts was associated with poor immunological recovery and compromised event-free survival (50% vs. 80%, HR 2.93, p = 0.015) both due to increased relapse incidence and non-relapse mortality. The significant independent predictor of moderate and severe chronic GVHD was the high prevalence of and iNKT, Vß11, and double-positive cells in the PBSC grafts from young donors (HR 2.75, p = 0.0483). No patterns could be identified for BM grafts and for plasma biomarkers.

Safe and Effective Delivery of Antitumor Drug Using Mesenchymal Stem Cells Impregnated with Submicron Carriers.

An important area in modern malignant tumor therapy is the optimization of antitumor drugs pharmacokinetics. The use of some antitumor drugs is limited in clinical practice due to their high toxicity. Therefore, the strategy for optimizing the drug pharmacokinetics focuses on the generation of high local concentrations of these drugs in the tumor area with minimal systemic and tissue-specific toxicity. This can be achieved by encapsulation of highly toxic antitumor drug (vincristine (VCR) that is 20-50 times more toxic than widely used the antitumor drug doxorubicin) into nano- and microcarriers with their further association into therapeutically relevant cells that possess the ability to migrate to sites of tumor. Here, we fundamentally examine the effect of drug carrier size on the behavior of human mesenchymal stem cells (hMSCs), including internalization efficiency, cytotoxicity, cell movement, to optimize the conditions for the development of carrier-hMSCs drug delivery platform. Using the malignant tumors derived from patients, we evaluated the capability of hMSCs associated with VCR-loaded carriers to target tumors using a three-dimensional spheroid model in collagen gel. Compared to free VCR, the developed hMSC-based drug delivery platform showed enhanced antitumor activity regarding those tumors that express CXCL12 (stromal cell-derived factor-1 (SDF-1)) gene, inducing directed migration of hMSCs via CXCL12 (SDF-1)/CXCR4 pathway. These results show that the combination of encapsulated antitumor drugs and hMSCs, which possess the properties of active migration into tumors, is therapeutically beneficial and demonstrated high efficiency and low systematic toxicity, revealing novel strategies for chemotherapy in the future.

Efficient gene editing via non-viral delivery of CRISPR-Cas9 system using polymeric and hybrid microcarriers.

CRISPR-Cas9 is a revolutionary genome-editing technology that has enormous potential for the treatment of genetic diseases. However, the lack of efficient and safe, non-viral delivery systems has hindered its clinical application. Here, we report on the application of polymeric and hybrid microcarriers, made of degradable polymers such as polypeptides and polysaccharides and modified by silica shell, for delivery of all CRISPR-Cas9 components. We found that these microcarriers mediate more efficient transfection than a commercially available liposome-based transfection reagent (>70% vs. <50% for mRNA, >40% vs. 20% for plasmid DNA). For proof-of-concept, we delivered CRISPR-Cas9 components using our capsules to dTomato-expressing HEK293T cells-a model, in which loss of red fluorescence indicates successful gene editing. Notably, transfection of indicator cells translated in high-level dTomato knockout in approx. 70% of transfected cells. In conclusion, we have provided proof-of-principle that our micro-sized containers represent promising non-viral platforms for efficient and safe gene editing.

Mesenchymal Stem Cells Engineering: Microcapsules-Assisted Gene Transfection and Magnetic Cell Separation.

Stem cell engineering-the manipulation and functionalization of stem cells involving genetic modification-can significantly expand their applicability for cell therapy in humans. Toward this aim, reliable, standardized, and cost-effective methods for cell manipulation are required. Here we explore the potential of magnetic multilayer capsules to serve as a universal platform for nonviral gene transfer, stem cell magnetization, and magnetic cell separation to improve gene transfer efficiency. In particular, the following experiments were performed: (i) a study of the process of internalization of magnetic capsules into stem cells, including capsule co-localization with established markers of endo-lysosomal pathway; (ii) characterization and quantification of capsule uptake with confocal microscopy, electron microscopy, and flow cytometry; (iii) intracellular delivery of messenger RNA and separation of gene-modified cells by magnetic cell sorting (MACS); and (iv) analysis of the influence of capsules on cell proliferation potential. Importantly, based on the internalization of magnetic capsules, transfected cells became susceptible to external magnetic fields, which made it easy to enrich gene-modified cells using MACS (purity ∼95%), and also to influence their migration behavior. In summary, our results underline the high potential of magnetic capsules in stem cell functionalization, namely (i) to increase gene-transfer efficiency and (ii) to facilitate enrichment and targeting of transfected cells. Finally, we did not observe a negative impact of the capsules used on the proliferative capacity of stem cells, proving their high biocompatibility.