Instructive Hydrogels for Primary Tumor Cell Culture: Current Status and Outlook

Research progress on the application of organoids in gynecological tumors

Organoids are in vitro 3D models that maintain their own tissue structure and function. They largely overcome the limitations of traditional tumor models and have become a powerful research tool in the field of oncology in recent years. Gynecological malignancies are major diseases that seriously threaten the life and health of women and urgently require the establishment of models with a high degree of similarity to human tumors for clinical studies to formulate individualized treatments. Currently, organoids are widely studied in exploring the mechanisms of gynecological tumor development as a means of drug screening and individualized medicine. Ovarian, endometrial, and cervical cancers as common gynecological malignancies have high morbidity and mortality rates among other gynecological tumors. Therefore, this study reviews the application of modelling, drug efficacy assessment, and drug response prediction for ovarian, endometrial, and cervical cancers, thereby clarifying the mechanisms of tumorigenesis and development, and providing precise treatment options for gynecological oncology patients.

Toward morphologically relevant extracellular matrix: nanofiber-hydrogel composites for tumor cell culture

The natural extracellular matrix (ECM) consists of a continuous integrated fibrin network and a negatively charged proteoglycan-based matrix. In this work, we report a novel three-dimensional nanofiber hydrogel composite that mimics the natural ECM structure, exhibiting both degradability and mechanical characteristics comparable to that of tumor tissue. The embedded nanofiber improves the hydrogel mechanical properties, and varying the fiber density can match the elastic modulus of different tumor tissues (1.51-10.77 kPa). The degradability of the scaffold gives sufficient space for tumor cells to secrete and remodel the ECM. The expression levels of cancer stem cell markers confirmed the development of aggressive and metastatic phenotypes of prostate cancer cells in the 3D scaffold. Similar results were obtained in terms of anticancer resistance of prostate cancer cells in 3D scaffolds showing stem cell-like properties, suggesting that the current bionic 3D scaffold tumor model has broad potential in the development of effective targeted agents.

Polyglycerol-Based Biomedical Matrix for Immunomagnetic Circulating Tumor Cell Isolation and Their Expansion into Tumor Spheroids for Drug Screening

Circulating tumor cells (CTCs) are established as distinct cancer biomarkers for diagnosis, as preclinical models, and therapeutic targets. Their use as preclinical models is limited owing to low purity after isolation and the lack of effective techniques to create 3D cultures that accurately mimic in vivo conditions. Herein, a two-component system for detecting, isolating, and expanding CTCs to generate multicellular tumor spheroids that mimic the physiology and microenvironment of the diseased organ is proposed. First, an antifouling biointerface on magnetic beads is fabricated by adding a bioinert polymer layer and conjugation of biospecific ligands to isolate cancer cells, dramatically enhancing the selectivity and purity of the isolated cancer cells. Next, the isolated cells are encapsulated into self-degradable hydrogels synthesized using a thiol-click approach. The hydrogels are mechanochemically tuned to enable tumor spheroid growth to a size greater than 300 µm and to further release the grown spheroids while retaining their tumor-like characteristics. In addition, drug treatment highlights the need for 3D culture environments rather than conventional 2D culture. The designed biomedical matrix shows potential as a universal method to ensure mimicry of in vivo tumor characteristics in individual patients and to improve the predictability of preclinical screening of personalized therapeutics.

Convenient tumor 3D spheroid arrays manufacturing via acoustic excited bubbles for in situ drug screening

The quick and convenient fabrication of in vitro tumor spheroids models has been pursued for clinical drug discovery and personalized therapy. Here, uniform three-dimensional (3D) tumor spheroids are quickly constructed by acoustically excited bubble arrays in a microfluidic chip and performed drug response testing in situ. In detail, bubble oscillation excited by acoustic waves induces second radiation force, resulting in the cells rotating and aggregating into tumor spheroids, which obtain controllable sizes ranging from 30 to 300 μm. These spherical tumor models are located in microfluidic networks, where drug solutions with gradient concentrations are generated from 0 to 18 mg mL^-1, so that the cell spheroids response to drugs can be monitored conveniently and efficiently. This one-step tumor spheroids manufacturing method significantly reduces the model construction time to less than 15 s and increases efficiency by eliminating additional transfer processes. These significant advantages of convenience and high-throughput manufacturing make the tumor models promising for use in tumor treatment and point-of-care diagnosis.

Recent advances on small molecular gels: formation mechanism and their application in pharmaceutical fields

INTRODUCTION

As an essential complement to chemically cross-linked macromolecular gels, drug delivery systems based on small molecular gels formed under the driving forces of non-covalent interactions are attracting considerable research interest due to their potential advantages of high structural functionality, lower biological toxicity, reversible stimulus-response, and so on.

AREA COVERED

The present review summarizes recent advances in small molecular gels and provides their updates as a comprehensive overview in terms of gelation mechanism, gel properties, and physicochemical characterizations. In particular, this manuscript reviews the effects of drug-based small molecular gels on the drug development and their potential applications in the pharmaceutical fields.

EXPERT OPINION

Small molecular-based gel systems, constructed by inactive compounds or active pharmaceutical ingredients, have been extensively studied as carriers for drug delivery in pharmaceutical field, such as oral formulations, injectable formulations, and transdermal formulations. However, the construction of such gel systems yet faces several challenges such as rational and efficient design of functional gelators and the great occasionality of drug-based gel formation. Thus, a deeper understanding of the gelation mechanism and its relationship with gel properties will be conducive to the construction of small molecular gels systems and their future application.