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.
One of the rapidly developing directions of biomedical research and nanotechnology is the design of new delivery systems, in particular, for the delivery of genetic information. Majority of the established immortalized cells lines broadly used by the scientific community allow efficient RNA and DNA transfer using lipid-, polysaccharide-, polymer-, or calcium precipitation-based commercially available reagents. However, manipulation of gene expression in primary cells, including adult and embryonic stem cells and cancer stem cells representing attractive tools for regenerative medicine, cancer therapy, and immune disease treatment, remains still an Efficient delivery of genetic material to primary cells remains challenging. Here, efficient transfer of genetic material is presented using synthetic biodegradable nanocarriers, resembling extracellular vesicles in their biomechanical properties. This is based on two main technological achievements: generation of soft biodegradable polyelectrolyte capsules in nanosize and efficient application of the nanocapsules for co-transfer of different RNAs to tumor cell lines and primary cells, including hematopoietic progenitor cells and primary T cells. Near to 100% efficiency is reached using only 2.5 × 10 −4 pmol of siRNA, and 1 × 10 −3 nmol of mRNA per cell, which is several magnitude orders below the amounts reported for any of methods published so far. The data show that biodegradable nanocapsules represent a universal and highly efficient biomimetic platform for the transfer of genetic material with the utmost potential to revolutionize gene transfer technology in vitro and in vivo.
Core–shell
particles made of calcium carbonate and coated with biocompatible
polymers using the Layer-by-Layer technique can be considered as a
unique drug-delivery platform that enables us to load different therapeutic
compounds, exhibits a high biocompatibility, and can integrate several
stimuli-responsive mechanisms for drug release. However, before implementation
for diagnostic or therapeutic purposes, such core–shell particles
require a comprehensive in vivo evaluation in terms
of physicochemical and pharmacokinetic properties. Positron emission
tomography (PET) is an advanced imaging technique for the evaluation
of in vivo biodistribution of drug carriers; nevertheless,
an incorporation of positron emitters in these carriers is needed.
Here, for the first time, we demonstrate the radiolabeling approaches
of calcium carbonate core–shell particles with different sizes
(CaCO3 micron-sized core–shell particles (MicCSPs)
and CaCO3 submicron-sized core–shell particles (SubCSPs))
to precisely determine their in vivo biodistribution
after intravenous administration in rats. For this, several methods
of radiolabeling have been developed, where the positron emitter (68Ga) was incorporated into the particle’s core (co-precipitation
approach) or onto the surface of the shell (either layer coating or
adsorption approaches). According to the obtained data, radiochemical
bounding and stability of 68Ga strongly depend on the used
radiolabeling approach, and the co-precipitation method has shown
the best radiochemical stability in human serum (96–98.5% for
both types of core–shell particles). Finally, we demonstrate
the size-dependent effect of core–shell particles’ distribution
on the specific organ uptake, using a combination of imaging techniques,
PET, and computerized tomography (CT), as well as radiometry of separate
organs. Thus, our findings open up new perspectives of CaCO3-radiolabeled core–shell particles for their further implementation
into clinical practice.
Growth
factor incorporation in biomedical constructs for their
local delivery enables specific pharmacological effects such as the
induction of cell growth and differentiation. This has enabled a promising
way to improve the tissue regeneration process. However, it remains
challenging to identify an appropriate approach that provides effective
growth factor loading into biomedical constructs with their following
release kinetics in a prolonged manner. In the present work, we performed
a systematic study, which explores the optimal strategy of growth
factor incorporation into sub-micrometric-sized CaCO3 core–shell
particles (CSPs) and hollow silica particles (SiPs). These carriers
were immobilized onto the surface of the polymer scaffolds based on
polyhydroxybutyrate (PHB) with and without reduced graphene oxide
(rGO) in its structure to examine the functionality of incorporated
growth factors. Bone morphogenetic protein-2 (BMP-2) and ErythroPOietin
(EPO) as growth factor models were included into CSPs and SiPs using
different entrapping strategies, namely, physical adsorption, coprecipitation
technique, and freezing-induced loading method. It was shown that
the loading efficiency, release characteristics, and bioactivity of
incorporated growth factors strongly depend on the chosen strategy
of their incorporation into delivery systems. Overall, we demonstrated
that the combination of scaffolds with drug delivery systems containing
growth factors has great potential in the field of tissue regeneration
compared with individual scaffolds.
While DNA and messenger RNA (mRNA) based therapies are currently changing the biomedical field, the delivery of genetic material remains the key problem preventing the wide introduction of these methods...
Actinium-225 (225Ac) radiolabeled
submicrometric core–shell
particles (SPs) made of calcium carbonate (CaCO3) coated
with biocompatible polymers [tannic acid–human serum albumin
(TA/HSA)] have been developed to improve the efficiency of local α-radionuclide
therapy in melanoma models (B16-F10 tumor-bearing mice). The developed 225Ac-SPs possess radiochemical stability and demonstrate effective
retention of 225Ac and its daughter isotopes. The SPs have
been additionally labeled with zirconium-89 (89Zr) to perform
the biodistribution studies using positron emission tomography–computerized
tomography (PET/CT) imaging for 14 days after intratumoral injection.
According to the PET/CT analysis, a significant accumulation of 89Zr-SPs in the tumor area is revealed for the whole investigation
period, which correlates with the direct radiometry analysis after
intratumoral administration of 225Ac-SPs. The histological
analysis has revealed no abnormal changes in healthy tissue organs
after treatment with 225Ac-SPs (e.g., no acute pathologic
findings are detected in the liver and kidneys). At the same time,
the inhibition of tumor growth has been observed as compared with
control samples [nonradiolabeled SPs and phosphate-buffered saline
(PBS)]. The treatment of mice with 225Ac-SPs has resulted
in prolonged survival compared to the control samples. Thus, our study
validates the application of 225Ac-doped core–shell
submicron CaCO3 particles for local α-radionuclide
therapy.
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