Assessment of an Integrative Anticancer Treatment Using an in Vitro Perfusion-Enabled 3D Breast Tumor Model

Functionalized manganese iron oxide nanoparticles: a dual potential magneto-chemotherapeutic cargo in a 3D breast cancer model

Localized heat generation from manganese iron oxide nanoparticles (MIONPs) conjugated with chemotherapeutics under the exposure of an alternating magnetic field (magneto-chemotherapy) can revolutionize targeted breast cancer therapy. On the other hand, the lack of precise control of local temperature and adequate MIONP distribution in laboratory settings using the conventional two-dimensional (2D) cellular models has limited its further translation in tumor sites. Our current study explored advanced 3D in vitro tumor models as a promising alternative to replicate the complete range of tumor characteristics. Specifically, we have focused on investigating the effectiveness of MIONP-based magneto-chemotherapy (MCT) as an anticancer treatment in a 3D breast cancer model. To achieve this, chitosan-coated MIONPs (CS-MIONPs) are synthesized and functionalized with an anticancer drug (doxorubicin) and a tumor-targeting aptamer (AS1411). CS-MIONPs with a crystallite size of 16.88 nm and a specific absorption rate (SAR) of 181.48 W g-1 are reported. In vitro assessment of MCF-7 breast cancer cell lines in 2D and 3D cell cultures demonstrated anticancer activity. In the 2D and 3D cancer models, the MIONP-mediated MCT reduced cancer cell viability to about 71.48% and 92.2%, respectively. On the other hand, MIONP-mediated MCT under an AC magnetic field diminished spheroids' viability to 83.76 ± 2%, being the most promising therapeutic modality against breast cancer.

3D printing-based drug-loaded implanted prosthesis to prevent breast cancer recurrence post-conserving surgery

Systemic chemotherapy of breast cancer is commonly delivered as a large dose and has toxic side effects. Local chemotherapy would overcome the shortcomings of systemic reconstruction and could play an important role in breast cancer surgery according to personalized demand. The application of three-dimensional (3D) printing technology makes personalized customization possible. We designed and prepared a prosthesis containing paclitaxel (PTX) and doxorubicin (DOX) microspheres (PPDM) based on 3D printing to prevent tumor recurrence and metastasis after breast conserving surgery. Polydimethysiloxane has good biocompatibility and was used as a drug carrier in this study. The average particle size of the PTX and DOX microspheres were approximately 3.1 µm and 2.2 µm, respectively. The drug loading of PTX and DOX microspheres was 4.2% and 2.1%, respectively. In vitro drug release studies demonstrated that the 3D-printed prosthesis loaded with PTX and DOX microspheres could release the drugs continuously for more than 3 weeks and thereby suppress cancer recurrence with reduced side effects. The PTX and DOX microspheres not only exerted a synergistic effect, but also achieved a good sustained release effect. In vivo evaluation showed that the PPDM could effectively inhibit breast cancer recurrence and metastasis in mice with breast cancer. PPDM are expected to achieve postoperative chemotherapy for breast cancer and be highly efficient to prevent local breast cancer recurrence and metastasis.

A Tumor-on-a-Chip System with Bioprinted Blood and Lymphatic Vessel Pair

Current in vitro anti-tumor drug screening strategies are insufficiently portrayed lacking true perfusion and draining microcirculation systems, which may post significant limitation in reproducing the transport kinetics of cancer therapeutics explicitly. Herein, we report the fabrication of an improved tumor model consisting of bioprinted hollow blood vessel and lymphatic vessel pair, hosted in a three-dimensional (3D) tumor microenvironment-mimetic hydrogel matrix, termed as the tumor-on-a-chip with bioprinted blood and lymphatic vessel pair (TOC-BBL). The bioprinted blood vessel was perfusable channel with opening on both ends while the bioprinted lymphatic vessel was blinded on one end, both of which were embedded in a hydrogel tumor mass, with vessel permeability individually tunable through optimization of the composition of the bioinks. We demonstrated that systems with different combinations of these bioprinted blood/lymphatic vessels exhibited varying levels of diffusion profiles for biomolecules and anti-cancer drugs. Our TOC-BBL platform mimicking the natural pathway of drug-tumor interactions would have the drug introduced through the perfusable blood vessel, cross the vascular wall into the tumor tissue via diffusion, and eventually drained into the lymphatic vessel along with the carrier flow. Our results suggested that this unique in vitro tumor model containing the bioprinted blood/lymphatic vessel pair may have the capacity of simulating the complex transport mechanisms of certain pharmaceutical compounds inside the tumor microenvironment, potentially providing improved accuracy in future cancer drug screening.

Engineering Breast Cancer Microenvironments and 3D Bioprinting

The extracellular matrix (ECM) is a critical cue to direct tumorigenesis and metastasis. Although two-dimensional (2D) culture models have been widely employed to understand breast cancer microenvironments over the past several decades, the 2D models still exhibit limited success. Overwhelming evidence supports that three dimensional (3D), physiologically relevant culture models are required to better understand cancer progression and develop more effective treatment. Such platforms should include cancer-specific architectures, relevant physicochemical signals, stromal-cancer cell interactions, immune components, vascular components, and cell-ECM interactions found in patient tumors. This review briefly summarizes how cancer microenvironments (stromal component, cell-ECM interactions, and molecular modulators) are defined and what emerging technologies (perfusable scaffold, tumor stiffness, supporting cells within tumors and complex patterning) can be utilized to better mimic native-like breast cancer microenvironments. Furthermore, this review emphasizes biophysical properties that differ between primary tumor ECM and tissue sites of metastatic lesions with a focus on matrix modulation of cancer stem cells, providing a rationale for investigation of underexplored ECM proteins that could alter patient prognosis. To engineer breast cancer microenvironments, we categorized technologies into two groups: (1) biochemical factors modulating breast cancer cell-ECM interactions and (2) 3D bioprinting methods and its applications to model breast cancer microenvironments. Biochemical factors include matrix-associated proteins, soluble factors, ECMs, and synthetic biomaterials. For the application of 3D bioprinting, we discuss the transition of 2D patterning to 3D scaffolding with various bioprinting technologies to implement biophysical cues to model breast cancer microenvironments.