On-chip fabrication of calcium carbonate nanoparticles loaded with various compounds using microfluidic approach.

Engineered calcium carbonate (CaCO3) particles are extensively used as drug delivery systems due to their availability, biological compatibility, biodegradability, and cost-effective production. The synthesis procedure of CaCO3 particles, however, suffers from poor reproducibility. Furthermore, reducing the size of CaCO3 particles to <100 nm requires the use of additives in the reaction, which increases the total reaction time. Here we propose on-chip synthesis and loading of nanoscaled CaCO3 particles using microfluidics. After the development and fabrication of a microfluidic device, we optimized the synthesis of CaCO3 NPs by varying different parameters such as flow rates in the microfluidic channels, concentration of reagents, and the reaction time. To prove the versatility of the used synthesis route, we performed single and double loading of CaCO3 NPs with various compounds (Doxorubicin, Cy5 or FITC conjugated with BSA, and DNA) using the same microfluidic device. Further, the on-chip loaded CaCO3 NPs were used as carriers to transfer compounds to model cells. We have developed a microfluidic synthesis method that opens up a new pathway for easy on-chip fabrication of functional nanoparticles for clinical use.

One-Pot Synthesis of Affordable Redox-Responsive Drug Delivery System Based on Trithiocyanuric Acid Nanoparticles.

Redox-responsive drug delivery systems present a promising avenue for drug delivery due to their ability to leverage the unique redox environment within tumor cells. In this work, we describe a facile and cost-effective one-pot synthesis method for a redox-responsive delivery system based on novel trithiocyanuric acid (TTCA) nanoparticles (NPs). We conduct a thorough investigation of the impact of various synthesis parameters on the morphology, stability, and loading capacity of these NPs. The great drug delivery potential of the system is further demonstrated in vitro and in vivo by using doxorubicin as a model drug. The developed TTCA-PEG NPs show great drug delivery efficiency with minimal toxicity on their own both in vivo and in vitro. The simplicity of this synthesis, along with the promising characteristics of TTCA-PEG NPs, paves the way for new opportunities in the further development of redox-responsive drug delivery systems based on TTCA.

Efficacy and safety of nivolumab combined with brentuximab vedotin after nivolumab monotherapy failure in patients with relapsed and refractory classic Hodgkin lymphoma.

OBJECTIVES: Therapy of patients with relapsed and refractory classic Hodgkin lymphoma (r/r cHL) after PD-1 inhibitors failure remains an unresolved issue. The aim of this study was to evaluate the efficacy and safety of the combination of nivolumab with brentuximab vedotin (Nivo + BV) after nivolumab monotherapy failure. METHODS: This study retrospectively analyzed 21 patients with r/r cHL who were treated with the combination of Nivo + BV after Nivo failure. The response was evaluated by PET-CT scan according to the LYRIC criteria. Adverse events (AEs) were assessed according to NCI CTCAE v.4.03. RESULTS: Median follow-up was 19 (9-47) months. The ORR was 57%. The median OS was not reached, 24 month OS was 80% (95% CI 50-93%). Median PFS was 12 months with 24 month PFS of 31% (95% CI 12-53%). Any grade AEs were observed in 12 patients (63%), 3-4 grade AEs in 2 patients (10%). Allogeneic hematopoietic stem cell transplantation (allo-HSCT) after Nivo + BV was performed in 8 (38%) patients. The median time between Nivo + BV and allo-HSCT was 8 (5-21) months. CONCLUSIONS: Combination of Nivo + BV in r/r cHL after nivolumab monotherapy failure is potentially an effective and safe approach.

Boosting transfection efficiency: A systematic study using layer-by-layer based gene delivery platform.

Nowadays, the nanoparticle-based delivery approach is becoming more and more attractive in gene therapy due to its low toxicity and immunogenicity, sufficient packaging capacity, targeting, and straightforward, low-cost, large-scale good manufacturing practice (GMP) production. A number of research works focusing on multilayer structures have explored different factors and parameters that can affect the delivery efficiency of pDNA. However, there are no systematic studies on the performance of these structures for enhanced gene delivery regarding the gene loading methods, the use of additional organic components and cell/particle incubation conditions. Here, we conducted a detailed analysis of different parameters such as (i) strategy for loading pDNA into carriers, (ii) incorporating both pDNA and organic additives within one carrier and (iii) variation of cell/particle incubation conditions, to evaluate their influence on the efficiency of pDNA delivery with multilayer structures consisting of inorganic cores and polymer layers. Our results reveal that an appropriate combination of all these parameters leads to the development of optimized protocols for high transfection efficiency, compared to the non-optimized process (> 70% vs. < 7%), and shows a good safety profile. In conclusion, we provide the proof-of-principle that these multilayer structures with the developed parameters are a promising non-viral platform for an efficient delivery of nucleic acids.

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.

Layer-by-Layer technique as a versatile tool for gene delivery applications.

Introduction: Gene therapy is a breakthrough medical field which focuses on the therapeutic delivery of recombinant nucleic acids in order to treat or prevent a broad spectrum of diseases. However, a number of important obstacles remain before its wide introduction into clinical practice can be envisaged. One of the biggest bottlenecks is the lack of efficient and safe delivery technologies, particularly, for in vivo distribution. Above and beyond standard requirements for carriers, the delivery systems for gene therapy ideally use a hit-and-run principle (to minimize off-target effect and display of immunogenic moieties). None of the currently used viral vectors fulfills all of these requirements. Therefore, the growing variety of non-viral delivery platforms represents a promising alternative.Areas covered: This review summarizes the Layer-by-Layer (LbL) approaches that can be effectively used for the gene delivery, considering various examples with the transfer of pDNA, mRNA, siRNA as well as genome-editing tools. Ex vivo gene modification of clinically relevant cells and clinical aspects for possible application of LbL systems in gene therapy are also underlined.Expert opinion: The LbL technique provides broad opportunities for the delivery of genetic material for various purposes and offers promise for future clinical application in gene therapy.

Nivolumab discontinuation and retreatment in patients with relapsed or refractory Hodgkin lymphoma.

Immune checkpoint inhibitors (ICI) have demonstrated high therapeutic efficacy in relapsed or refractory classical Hodgkin lymphoma (r/r cHL). Nevertheless, despite the accumulated data, the question of the ICI therapy duration and efficacy of nivolumab retreatment remains unresolved. In this retrospective study, in a cohort of 23 adult patients with r/r cHL who discontinued nivolumab in complete response (CR), the possibility of durable remission achievement (2-year PFS was 55.1%) was demonstrated. Retreatment with nivolumab has demonstrated efficacy with high overall response rate (ORR) and CR (67% and 33.3% respectively). At the final analysis, all patients were alive with median PFS of 16.5 months. Grade 3-4 adverse events (AEs) were reported in 36% of patients, and there was no deterioration in terms of nivolumab retreatment-associated complications.

A Phase 2 Study of Nivolumab Using a Fixed Dose of 40 mg (Nivo40) in Patients With Relapsed/Refractory Hodgkin Lymphoma.

The introduction of nivolumab has changed the landscape of relapsed/refractory classical Hodgkin lymphoma (r/r cHL) treatment. Despite its clinical importance, this therapy may remain inaccessible for a significant number of patients worldwide, especially in low-income countries, due to its high cost. The results of pharmacokinetic analysis and clinical observations suggest the potential efficacy of low dose nivolumab in r/r cHL patients. The aim of this trial was to assess the efficacy and safety of nivolumab at a fixed dose of 40 mg in patients with r/r cHL. The study included 30 patients with r/r cHL, treated with 40 mg nivolumab every 2 weeks. The median dose of nivolumab per kilogram bodyweight was 0.59 mg/kg (0.4-1 mg/kg). Median follow up was 19.2 months (range 12.7-25.4). The objective response rate was 70%, with 13 (43.3%) patients achieving a complete response. Median PFS was 18.4 months (95% CI, 11.3 to 18.5 months) with 18-month PFS of 53.6% (95% CI, 32%-71%). At the time of analysis, 96.7% of patients were alive with a median OS not reached. Severe (grade 3-5) adverse events were observed in 4 patients (13.3%). Nivolumab in a fixed dose of 40 mg was efficient in patients with r/r cHL, independent from dose per kg bodyweight. The results of this study are in good agreement with previously reported data and create a rationale for further studies aimed to define the optimal dosing regimen of nivolumab for the treatment of r/r cHL. Registered at www.clinicaltrials.gov (NCT03343665).

DDAO Controlled Synthesis of Organo-Modified Silica Nanoparticles with Encapsulated Fluorescent Boron Dipyrrins and Study of Their Uptake by Cancerous Cells.

The design of cargo carriers with high biocompatibility, unique morphological characteristics, and capability of strong bonding of fluorescent dye is highly important for the development of a platform for smart imaging and diagnostics. In this paper, BODIPY-doped silica nanoparticles were prepared through a "one-pot" soft-template method using a sol-gel process. Several sol-gel precursors have been used in sol-gel synthesis in the presence of soft-template to obtain the silica-based materials with the most appropriate morphological features for the immobilization of BODIPY molecules. Obtained silica particles have been shown to be non-cytotoxic and can be effectively internalized into the cervical cancer cell line (HeLa). The described method of synthesis allows us to obtain silica-based carriers with an immobilized fluorescent dye that provide the possibility for real-time imaging and detection of these carriers.

Overcoming the delivery problem for therapeutic genome editing: Current status and perspective of non-viral methods.

Besides its broad application in research and biotechnology, genome editing (GE) has great potential for clinical gene therapy, but delivery of GE tools remains a bottleneck. Whereas significant progress has been made in ex vivo GE delivery (e.g., by electroporation), establishment of efficient and safe in vivo delivery systems is still a challenge. Above and beyond standard vector requirements (safety, minimal/absent toxicity and immunogenicity, sufficient packaging capacity, targeting, straight and low-cost large-scale good manufacturing practice (GMP) production), GE delivery systems ideally use a hit-and-run principle to minimize off-targets as well as display of immunogenic peptides. Since currently used viral vectors do not fulfil all of these requirements, the broad variety of non-viral delivery platforms represents a promising alternative. This review provides a comprehensive analysis of the most relevant aspects of non-viral physical and chemical delivery methods in non-clinical studies and clinical trials, ranging from classic electroporation to advanced drug carriers that can transport GE tools in form of plasmid DNAs (pDNAs), mRNAs, and ribonucleoproteins (RNPs). For comparison, advantages and shortcomings of viral delivery systems are shortly discussed. In summary, we review various delivery approaches and discuss the future perspectives to use drug carriers for in vivo GE in clinical trials.

A Study of Safety and Efficacy of Nivolumab and Bendamustine (NB) in Patients With Relapsed/Refractory Hodgkin Lymphoma After Nivolumab Monotherapy Failure.

This single-center prospective clinical trial evaluated the combination of nivolumab plus bendamustine (NB) as a salvage regimen in classical Hodgkin lymphoma patients after failure of nivolumab monotherapy. A total of 30 patients received nivolumab (3 mg/kg) on D1,14 and bendamustine (90 mg/m2) on D1, 2 of a 28-day cycle for up to 3 cycles. The ORR was 87% with 57% CR, 30% PR. With median follow-up of 25 months, the estimated 2-year OS was 96,7% (95% CI, 90.2%-100%), PFS was 23,3% (95% CI, 8.2%-38.4%) median PFS was 10.2 months (95% CI, 7.7-14.2 months) with median DOR 6.6 months (95% CI 3.9-11.6 months). Ten patients (33.3%) experienced grade 3 to 4 AE during therapy. Infections were most common AEs of the combined therapy. NB was a highly efficient salvage regimen in relapsed/refractory cHL with a manageable toxicity profile and modest potential for achievement of long-term remission. Registered at www.clinicaltrials.gov (#NCT0334365).

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.

A comparison study between electrospun polycaprolactone and piezoelectric poly(3-hydroxybutyrate-co-3-hydroxyvalerate) scaffolds for bone tissue engineering.

In this study, bone scaffolds composed of polycaprolactone (PCL), piezoelectric poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and a combination of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and silicate containing hydroxyapatite (PHBV-SiHA) were successfully fabricated by a conventional electrospinning process. The morphological, chemical, wetting and biological properties of the scaffolds were examined. All fabricated scaffolds are composed of randomly oriented fibres with diameters from 800nm to 12µm. Fibre size increased with the addition of SiHA to PHBV scaffolds. Moreover, fibre surface roughness in the case of hybrid scaffolds was also increased. XRD, FTIR and Raman spectroscopy were used to analyse the chemical composition of the scaffolds, and contact angle measurements were performed to reveal the wetting behaviour of the synthesized materials. To determine the influence of the piezoelectric nature of PHBV in combination with SiHA nanoparticles on cell attachment and proliferation, PCL (non-piezoelectric), pure PHBV, and PHBV-SiHA scaffolds were seeded with human mesenchymal stem cells (hMSCs). In vitro study on hMSC adhesion, viability, spreading and osteogenic differentiation showed that the PHBV-SiHA scaffolds had the largest adhesion and differentiation abilities compared with other scaffolds. Moreover, the piezoelectric PHBV scaffolds have demonstrated better calcium deposition potential compared with non-piezoelectric PCL. The results of the study revealed pronounced advantages of hybrid PHBV-SiHA scaffolds to be used in bone tissue engineering.

Hybrid inorganic-organic capsules for efficient intracellular delivery of novel siRNAs against influenza A (H1N1) virus infection.

The implementation of RNAi technology into the clinical practice has been significantly postponing due to the issues regarding to the delivery of naked siRNA predominantly to target cells. Here we report the approach to enhance the efficiency of siRNA delivery by encapsulating the siRNA into new carrier systems which are obtained via the combination of widely used layer-by-layer technique and in situ modification by sol-gel chemistry. We used three types of siRNAs (NP-717, NP-1155 and NP-1496) in encapsulated form as new therapeutic agents against H1N1 influenza virus infection. By employing the hybrid microcontainers for the siRNA encapsulation we demonstrate the reduction of viral nucleoprotein (NP) level and inhibition of influenza virus production in infected cell lines (MDCK and A549). The obtained hybrid carriers based on assembled biodegradable polyelectrolytes and sol-gel coating possess several advantages such as a high cell uptake efficiency, low toxicity, efficient intracellular delivery of siRNAs and the protection of siRNAs from premature degradation before reaching the target cells. These findings underpin a great potential of versatile microencapsulation technology for the development of anti-viral RNAi delivery systems against influenza virus infection.

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.

Mesenchymal Stem Cell Magnetization: Magnetic Multilayer Microcapsule Uptake, Toxicity, Impact on Functional Properties, and Perspectives for Magnetic Delivery.

Mesenchymal stem cells (MSCs) are widely used in cell therapy due to their convenience, multiline differentiation potential, reproducible protocols, and biological properties. The potential of MSCs to impregnate magnetic microcapsules and their possible influence on cell function and ability to response to magnetic field have been explored. Interestingly, the cells suspended in media show much higher ability in internalization of microcapsules, then MSCs adhere into the surface. There is no significant effect of microcapsules on cell toxicity compared with other cell line-capsule internalization reported in literature. Due to internalization of magnetic capsules by the cells, such cell engineering platform is responsive to external magnetic field, which allows to manipulate MSC migration. Magnetically sorted MSCs are capable to differentiation as confirmed by their conversion to adipogenic and osteogenic cells using standard protocols. There is a minor effect of capsule internalization on cell adhesion, though MSCs are still able to form spheroid made by dozen of thousand MSCs. This work demonstrates the potential of use of microcapsule impregnated MSCs to carry internalized micron-sized vesicles and being navigated with external magnetic signaling.

Intracellular redox induced drug release in cancerous and mesenchymal stem cells.

In this report, we investigated intracellular redox induced drug release in cancerous cells and human mesenchymal stem cells (MSCs) as an example of healthy cells using redox-responsive microcapsules with covalently bonded anti-cancer drug (doxorubicin) via the amine-reactive cross-linker, 3,3'-dithiobis(sulfosuccinimidyl propionate) containing disulfide bond. Such rationally designed capsules with incorporated redox-sensitive cross-linker are capable of controllable Dox release in the presence of glutathione (GSH) due to a thiol-cleavable disulfide bonds. The treatment of human MSCs and human cervical cancer cell line (HeLa) with Dox-conjugated capsules showed that the Dox release was observed only when capsules incubated with HeLa cells which can be induced by high GSH level in cancerous (HeLa) cells. Moreover, the results of cell viability indicated that Dox-conjugated capsules are more effective when inducing cell death of HeLa than free Dox improving the anti-tumor efficacy of chemotherapeutic drug and simultaneously they possess lower cytotoxicity against MSCs compared to cancerous cells. Such properties are important in design of smart drug carriers for efficient cancer therapy.

Triple-responsive inorganic-organic hybrid microcapsules as a biocompatible smart platform for the delivery of small molecules.

We designed novel hybrid inorganic/organic capsules with unique physicochemical features enabling multimodal triggering by physical (UV light, ultrasound) and chemical (enzymatic treatment) stimuli. Notably, the UV- and ultrasound response was achieved by a synergetic combination of TiO2 and SiO2 nanostructures which were in situ deposited into the polymer shell of microcapsules during sol-gel synthesis. This results in the formation of a composite hybrid shell with enhanced mechanical stability. Such sol-gel modification reduces the permeability of the capsule shell to allow for small molecule encapsulation. At the same time, these hybrid capsules consist of degradable polypeptides and polysaccharides and can be decomposed in response to enzymatic reaction. Upon employing different modes of treatment (UV-light, ultrasound or enzymatic degradation) we can stimulate different mechanisms of cargo release at desired times. Importantly, such capsules have been shown to be non-cytotoxic and can be internalized into human mesenchymal stem cells (MSCs) and cervical cancer cell lines (HeLa) revealing intracellular degradation. This work demonstrates that our hybrid capsules possess a triple stimuli-responsive effect, which is of capital importance for the future design and application of multimodal responsive platforms to improve externally stimulated release of bioactive compounds and their healthcare performance.