Cell deformation and acquired drug resistance: elucidating the major influence of drug-nanocarrier delivery systems

Chemical tunability of advanced materials used in the fabrication of micro/nanobots

Micro and nanobots (MNBs) are unprecedented in their ability to be chemically tuned for autonomous tasks with enhanced targeting and functionality while maintaining their mobility. A myriad of chemical modifications involving a large variety of advanced materials have been demonstrated to be effective in the design of MNBs. Furthermore, they can be controlled for their autonomous motion, and their ability to carry chemical or biological payloads. In addition, MNBs can be modified to achieve targetability with specificity for biological implications. MNBs by virtue of their chemical compositions may be limited by their biocompatibility, tissue accumulation, poor biodegradability and toxicity. This review presents a note on artificial intelligence materials (AIMs), their importance, and the dimensional scales at which intrinsic autonomy can be achieved for diverse utility. We briefly discuss the evolution of such systems with a focus on their advancements in nanomedicine. We highlight MNBs covering their contemporary traits and the emergence of a few start-ups in specific areas. Furthermore, we showcase various examples, demonstrating that chemical tunability is an attractive primary approach for designing MNBs with immense capabilities both in biology and chemistry. Finally, we cover biosafety and ethical considerations in designing MNBs in the era of artificial intelligence for varied applications.

Current Molecular Combination Therapies Used for the Treatment of Breast Cancer

Breast cancer is the second leading cause of death for women worldwide. While monotherapy (single agent) treatments have been used for many years, they are not always effective, and many patients relapse after initial treatment. Moreover, in some patients the response to therapy becomes weaker, or resistance to monotherapy develops over time. This is especially problematic for metastatic breast cancer or triple-negative breast cancer. Recently, combination therapies (in which two or more drugs are used to target two or more pathways) have emerged as promising new treatment options. Combination therapies are often more effective than monotherapies and demonstrate lower levels of toxicity during long-term treatment. In this review, we provide a comprehensive overview of current combination therapies, including molecular-targeted therapy, hormone therapy, immunotherapy, and chemotherapy. We also describe the molecular basis of breast cancer and the various treatment options for different breast cancer subtypes. While combination therapies are promising, we also discuss some of the challenges. Despite these challenges, the use of innovative combination therapy holds great promise compared with traditional monotherapies. In addition, the use of multidisciplinary technologies (such as nanotechnology and computer technology) has the potential to optimize combination therapies even further.

Antibody mediated cotton-archetypal substrate for enumeration of circulating tumor cells and chemotherapy outcome in 3D tumors

Circulating tumor cells (CTCs) are distinct cancer biomarkers established in clinical settings for early cancer detection, metastasis progression, and minimal residual disease (MRD) monitoring. Despite numerous advances, the comprehensive molecular characterization of CTCs is extremely challenging owing to their rarity and heterogeneity. Here, we present a novel cotton microfluidic substrate (CMS) as an innovative biomedical matrix that efficiently isolates CTCs while facilitating in vitro CTC expansion to enable a further downstream analysis of these rare cells. CMS enabled static and dynamic isolation of cells from the MCF-7 cancer cell line, as well as from head and neck squamous cell carcinoma (HNSCC) patients' blood and the cell capture efficiencies were further compared with a clinically regulated OncoDiscover® Liquid Biopsy Test. Further, CMS acted as a matrix on which the captured cancer cells were grown in 3D tumor models for studying anti-cancer drug efficacy and multi-drug resistance (MDR) mechanisms. The design of the CMS employed two different surface chemistries, flattened and nanostructured surfaces, each conjugated to anti-EpCAM antibodies to evaluate the CTC capture efficiency and 3D tumor growth dynamics. The nanostructured surface was highly efficient for capturing CTCs and promoted 3D tumor spheroid formation with a 5-fold increase in size from day 03 to day 10 of culture. Moreover, when treated with an anti-cancer drug, cisplatin, an almost 1/2 reduction in tumor size was achieved within 24 hours, followed by a cytostatic threshold and eventual acquisition of drug resistance within 3 days. Conclusively, the CMS matrix exhibits potential for further development of "tissue on chip" and "point-of-care" medical devices in cancer diagnostics, and chemo-therapeutic efficacy evaluations in both drug discovery and development.

Ultrasonic Formation of Fe3O4-Reduced Graphene Oxide-Salicylic Acid Nanoparticles with Switchable Antioxidant Function

We demonstrate a single-step ultrasonic in situ complexation of salicylic acid during the growth of Fe₃O₄-reduced graphene oxide nanoparticles (∼10 nm) to improve the antioxidant and antiproliferative effects of pristine drug molecules. These nanoparticles have a precisely defined electronic molecular structure with salicylic acid ligands specifically complexed to Fe(III)/Fe(II) sites, four orders of magnitude larger electric surface potential, and enzymatic activity modulated by ascorbic acid molecules. The diminishing efficiency of hydroxyl radicals by Fe₃O₄-rGO-SA nanoparticles is tenfold higher than that by pristine salicylic acid in the electro-Fenton process. The H⁺ production of these nanoparticles can be switched by the interaction with ascorbic acid ligands and cause the redox deactivation of iron or enhanced antioxidation, where rGO plays an important role in enhanced charge transfer catalysis. Fe₃O₄-rGO-SA nanoparticles are nontoxic to erythrocytes, i.e., human peripheral blood mononuclear cells, but surpassingly inhibit the growth of three cancer cell lines, HeLa, HepG2, and HT29, with respect to pristine salicylic acid molecules.

Mammary Tumor Organoid Culture in Non-Adhesive Alginate for Luminal Mechanics and High-Throughput Drug Screening

Mammary tumor organoids have become a promising in vitro model for drug screening and personalized medicine. However, the dependency on the basement membrane extract (BME) as the growth matrices limits their comprehensive application. In this work, mouse mammary tumor organoids are established by encapsulating tumor pieces in non-adhesive alginate. High-throughput generation of organoids in alginate microbeads is achieved utilizing microfluidic droplet technology. Tumor pieces within the alginate microbeads developed both luminal- and solid-like structures and displayed a high similarity to the original fresh tumor in cellular phenotypes and lineages. The mechanical forces of the luminal organoids in the alginate capsules are analyzed with the theory of the thick-wall pressure vessel (TWPV) model. The luminal pressure of the organoids increase with the lumen growth and can reach 2 kPa after two weeks' culture. Finally, the mammary tumor organoids are treated with doxorubicin and latrunculin A to evaluate their application as a drug screening platform. It is found that the drug response is related to the luminal size and pressures of organoids. This high-throughput culture for mammary tumor organoids may present a promising tool for preclinical drug target validation and personalized medicine.

Designing 3D-nanosubstrates mimicking biological cell growth: pitfalls of using 2D substrates in the evaluation of anticancer efficiency

Designing nano-substrates (NS) that support three-dimensional (3D) cell growth using physico-chemical interventions mimicking the cellular microenvironment is highly challenging. Here we report NS that assist 3D cell development (3D NS) using multi-components on a glass substrate (2D GS), which mimics the ex vivo tissue microenvironment and promotes 3D cell growth superior to conventional 2D cell culturing methodologies. 3D NS were chemically fabricated by linking the combination of advanced materials imparting different physico-chemical traits, for example, multiwalled carbon nanotubes (CNT), graphene (G), bovine serum albumin (BSA), and iron oxide magnetic nanoparticles (MNP). We compared cell-substrate interactions resulting in cellular morphological changes, influence on the cell circularity index (CI), nuclear-cytoplasmic ratios (N/C), and nuclear compression or derangements using human colorectal carcinoma cells (HCT116) and cervical cancer (HeLa) cells. We observed the increase in N/C, extended on the 3D NS micro-environment as indicative of cellular adaptation and the transformation. HCT116 and HeLa cells on 2D GS showed an N/C ratio <0.3, and 3D NS cultured cells exhibited a higher N/C ratio (>0.5). The most significant increase in the ratio, relative to arrested cell spreading, was observed with G-3D NS. Furthermore, 3D NS were evaluated for the cell viability differentiations using the anticancer drug doxorubicin (Dox). The drug-treated cells on 3D NS demonstrated far-displaced N/C ratios compared to 2D GS. In conclusion, 3D NS systems implicate an 'in vitro to in vivo' relevance for the outcome in cell biology, cell proliferation and migration, and in anticancer drug efficacy evaluation.

A graphene-sandwiched DNA nano-system: regulation of intercalated doxorubicin for cellular localization

Control of the sub-cellular localization of nanoparticles (NPs) with enhanced drug-loading capacity, employing graphene oxide (GO), iron oxide (Fe3O4) NPs and sandwiched deoxyribonucleic acid (DNA) bearing intercalated anticancer drug doxorubicin (DOX) has been investigated in this work. The nanosystems G-DNA-DOX-Fe3O4 and Fe3O4-DNA-DOX differentially influence serum protein binding and deliver DOX to lysosomal compartments of cervical cancer (HeLa) cells with enhanced retention. Stern-Volmer plots describing BSA adsorption on the nanosystems demonstrated the quenching constants, K sv for G-DNA-DOX-Fe3O4 and Fe3O4-DNA-DOX (0.025 mL μg-1 and 0.0103 mL μg-1 respectively). Nuclear DOX intensity, measured at 24 h, was ∼2.0 fold higher for Fe3O4-DNA-DOX in HeLa cells. Parallelly, the cytosol displayed ∼2.2 fold higher DOX intensity for Fe3O4-DNA-DOX compared to G-DNA-DOX-Fe3O4. Fe3O4-DNA-DOX was more efficacious in the cytotoxic effect than G-DNA-DOX-Fe3O4 (viability of treated cells: 33% and 49% respectively). The DNA:nanosystems demonstrated superior cytotoxicity compared to mole-equivalent free DOX administration. The results implicate DNA:DOX NPs in influencing the cellular uptake mechanism and were critically subject to cellular localization. Furthermore, cell morphology analysis evidenced maximum deformation attributed to free-DOX with 34% increased cell roundness, 63% decreased cell area and ∼1.9 times increased nuclear-to-cytoplasmic (N/C) ratio after 24 h. In the case of Fe3O4-DNA-DOX, the N/C ratio increased 1.2 times and a maximum ∼37% decrease in NSA was noted suggesting involvement of non-canonical cytotoxic pathways. In conclusion, the study makes a case for designing nanosystems with controlled and regulated sub-cellular localization to potentially exploit secondary cytotoxic pathways, in addition to optimized drug-loading for enhanced anticancer efficacy and reduced adverse effects.

Nanocarrier anticancer drug-conjugates cause higher cellular deformations: culpable for mischief

Here we report nanocarrier-anticancer drug conjugates culpable for cellular deformations, critically evidenced through image-based analysis as a measure of karyoplasmic ratio (KR) and nuclear surface area (NSA). Multiwalled carbon nanotubes (MWCNTs) were coordinated additionally with Fe3O4 nanoparticles (NPs) to evaluate the symbiotic influence, and further conjugated to Dox for evaluating the cellular kinetics and for measuring cell deformations. Cellular entry kinetics of the CNT (CNT-Dox and CNT-Cys-Fe3O4-Dox) nanocarriers and their efficiency in nuclear localization were evaluated using cervical cancer (HeLa) cells. Of note, the Dox-bound nanocarriers showed significantly enhanced cell toxicity over the free form of the drug. CNT-Dox and CNT-Cys-Fe3O4-Dox influx occurred within 4 hours, while maximum cellular retention of Dox was observed for CNT-Dox at 24 h. However, the highest KR (∼0.51) was observed for CNT-Dox within 8 hours indicating similar cellular deformations using nanocarrier anticancer drug-conjugates to that of free Dox (KR ∼0.50) at 4 hours. In addition, we observed increased NSA at 4 h in Dox treatment whereas in the case of the Dox conjugated nanocarrier, increased NSA was noted at 8 h treatment. At 8 h exposure of HeLa cells with Dox conjugates, we observed that the cells fall into distinct regions of the morphospace with respect to KR and NSA. Conclusively, nano delivery systems considered for clinical and biomedical translations must take into account the possible negative influences imparting higher cellular deformations and secondary adverse effects over the free form of the drug.

Cellular regeneration and proliferation on polymeric 3D inverse-space substrates and the effect of doxorubicin

Spatial arrangement for cells and the opportunity thereof have implications in cell regeneration and cell proliferation. 3D inverse space (3DIS) substrates with micron-sized pores are fabricated under controlled environmental conditions from polymers such as poly(lactic-co-glycolic) acid (PLGA), poly(lactic acid) (PLA) and poly(styrene) (PS). The characterization of 3DIS substrates by optical microscopy, scanning probe microscopy (SPM), etc. shows pores within 1-18 μm diameter and prominent surface roughness extending up to 3.9 nm in height over its base. Conversely, to compare two-dimensional (2D) versus 3DIS substrates, the crucial variables of cell height, cell spreading area and cell volume are compared using lung adenocarcinoma (A549) cells. The results indicate an average cell thickness of ∼6 μm on a glass substrate whereas cells on PLGA 3DIS were ∼12 μm in height, occasionally reaching 20 μm, with a 40% decreased cell spreading area. A549 cells cultured on polymer 3DIS substrates show a cell regeneration growth pattern, dependent on the available spatial volume. Furthermore, PLGA 3DIS cell culture systems with and without graded doxorubicin (DOX) pre-treatment result in potent cell inhibition and cell proliferation, respectively. Additionally, standard DOX administration to A549 cells in the PLGA 3DIS system revealed altered drug sensitivity. 3DIS demonstrates utility in facilitating cellular regeneration and mimicking cell proliferation in defined spatial arrangements.