Evaluation of PEG-based hydrogel influence on estrogen receptor driven responses in MCF7 breast cancer cells

Exploring New Dimensions of Tumor Heterogeneity: The Application of Single Cell Analysis to Organoid-Based 3D In Vitro Models

Modeling the heterogeneity of the tumor microenvironment (TME) in vitro is essential to investigating fundamental cancer biology and developing novel treatment strategies that holistically address the factors affecting tumor progression and therapeutic response. Thus, the development of new tools for both in vitro modeling, such as patient-derived organoids (PDOs) and complex 3D in vitro models, and single cell omics analysis, such as single-cell RNA-sequencing, represents a new frontier for investigating tumor heterogeneity. Specifically, the integration of PDO-based 3D in vitro models and single cell analysis offers a unique opportunity to explore the intersecting effects of interpatient, microenvironmental, and tumor cell heterogeneity on cell phenotypes in the TME. In this review, the current use of PDOs in complex 3D in vitro models of the TME is discussed and the emerging directions in the development of these models are highlighted. Next, work that has successfully applied single cell analysis to PDO-based models is examined and important experimental considerations are identified for this approach. Finally, open questions are highlighted that may be amenable to exploration using the integration of PDO-based models and single cell analysis. Ultimately, such investigations may facilitate the identification of novel therapeutic targets for cancer that address the significant influence of tumor-TME interactions.

Multi compartmental 3D breast cancer disease model–recapitulating tumor complexity in in-vitro

Breast cancer is the most common ailment among women. In 2020, it had the highest incidence of any type of cancer. Many Phase II and III anti-cancer drugs fail due to efficacy, durability, and side effects. Thus, accelerated drug screening models must be accurate. In-vivo models have been used for a long time, but delays, inconsistent results, and a greater sense of responsibility among scientists toward wildlife have led to the search for in-vitro alternatives. Stromal components support breast cancer growth and survival. Multi-compartment Transwell models may be handy instruments. Co-culturing breast cancer cells with endothelium and fibroblasts improves modelling. The extracellular matrix (ECM) supports native 3D hydrogels in natural and polymeric forms. 3D Transwell cultured tumor spheroids mimicked in-vivo pathological conditions. Tumor invasion, migration, Trans-endothelial migration, angiogenesis, and spread are studied using comprehensive models. Transwell models can create a cancer niche and conduct high-throughput drug screening, promising future applications. Our comprehensive shows how 3D in-vitro multi compartmental models may be useful in producing breast cancer stroma in Transwell culture.

Recent progress of hydrogel-based local drug delivery systems for postoperative radiotherapy

Surgical resection and postoperative radiotherapy remained the most common therapeutic modalities for malignant tumors. However, tumor recurrence after receiving such combination is difficult to be avoided because of high invasiveness and radiation resistance of cancer cells during long-term therapy. Hydrogels, as novel local drug delivery systems, presented excellent biocompatibility, high drug loading capacity and sustained drug release property. Compared with conventional drug formulations, hydrogels are able to be administered intraoperatively and directly release the entrapped therapeutic agents to the unresectable tumor sites. Therefore, hydrogel-based local drug delivery systems have their unique advantages especially in sensitizing postoperative radiotherapy. In this context, classification and biological properties of hydrogels were firstly introduced. Then, recent progress and application of hydrogels for postoperative radiotherapy were summarized. Finally, the prospects and challenges of hydrogels in postoperative radiotherapy were discussed.

The Synthesis of Biodegradable Poly(L-Lactic Acid)-Polyethylene Glycols Copolymer/Montmorillonite Nanocomposites and Analysis of the Crystallization Properties

This study makes use of polycondensation to produce poly (L-lactic acid)-(polyethylene glycols), a biodegradable copolymer, then puts it with organically modified montmorillonite (o-MMT) going through an intercalation process to produce a series of nanocomposites of PLLA-PEG/o-MMT. The exfoliation and intercalation of the montmorillonite-layered structure could be found through X-ray diffraction and transmission electron microscopy. The lower the molecular weight of poly (ethylene glycol), the more obvious the exfoliation and dispersion. The nanocomposites were investigated under non-isothermal crystallization and isothermal crystallization separately via differential scanning calorimetry (DSC). After the adding of o-MMT to PLLA-PEG copolymers, it was found that the PLLA-PEG nanocomposites crystallized slowly and the crystallization peak tended to become broader during the non-isothermal crystallization process. Furthermore, the thermal curve of the non-isothermal melt crystallization process of PLLA-PEG copolymers with different proportions of o-MMT showed that the melting point decreased gradually with the increase of o-MMT content. In the measurement of isothermal crystallization, increasing the o-MMT of the PLLA-PEG copolymers would increase the t1/2 (crystallization half time) for crystallization and decrease the value of ΔHc. However, the present study results suggest that adding o-MMT could affect the crystallization rate of PLLA-PEG copolymers. The o-MMT silicate layer was uniformly dispersed in the PLLA-PEG copolymers, forming a nucleating agent. The crystallization rate and the regularity of the crystals changed with the increase of the o-MMT content, which further affected the crystallization enthalpies.

Atlas of Lobular Breast Cancer Models: Challenges and Strategic Directions

Invasive lobular carcinoma (ILC) accounts for up to 15% of all breast cancer (BC) cases and responds well to endocrine treatment when estrogen receptor α-positive (ER+) yet differs in many biological aspects from other ER+ BC subtypes. Up to 30% of patients with ILC will develop late-onset metastatic disease up to ten years after initial tumor diagnosis and may experience failure of systemic therapy. Unfortunately, preclinical models to study ILC progression and predict the efficacy of novel therapeutics are scarce. Here, we review the current advances in ILC modeling, including cell lines and organotypic models, genetically engineered mouse models, and patient-derived xenografts. We also underscore four critical challenges that can be addressed using ILC models: drug resistance, lobular tumor microenvironment, tumor dormancy, and metastasis. Finally, we highlight the advantages of shared experimental ILC resources and provide essential considerations from the perspective of the European Lobular Breast Cancer Consortium (ELBCC), which is devoted to better understanding and translating the molecular cues that underpin ILC to clinical diagnosis and intervention. This review will guide investigators who are considering the implementation of ILC models in their research programs.

Advancement of Scaffold-Based 3D Cellular Models in Cancer Tissue Engineering: An Update

The lack of traditional cancer treatments has resulted in an increased need for new clinical techniques. Standard two-dimensional (2D) models used to validate drug efficacy and screening have a low in vitro-in vivo translation potential. Recreating the in vivo tumor microenvironment at the three-dimensional (3D) level is essential to resolve these limitations in the 2D culture and improve therapy results. The physical and mechanical environments of 3D culture allow cancer cells to expand in a heterogeneous manner, adopt different phenotypes, gene and protein profiles, and develop metastatic potential and drug resistance similar to human tumors. The current application of 3D scaffold culture systems based on synthetic polymers or selected extracellular matrix components promotes signalling, survival, and cancer cell proliferation. This review will focus on the recent advancement of numerous 3D-based scaffold models for cancer tissue engineering, which will increase the predictive ability of preclinical studies and significantly improve clinical translation.

Tunable Cross-Linking and Adhesion of Gelatin Hydrogels via Bioorthogonal Click Chemistry

Engineering cytocompatible hydrogels with tunable physico-mechanical properties as a biomimetic three-dimensional extracellular matrix (ECM) is fundamental to guide cell response and target tissue regeneration or development of in vitro models. Gelatin represents an optimal choice given its ECM biomimetic properties; however, gelatin cross-linking is required to ensure structural stability at physiological temperature (i.e., T > T_{sol-gel gelatin}). Here, we use a previously developed cross-linking reaction between tetrazine (Tz)- and norbornene (Nb) modified gelatin derivatives to prepare gelatin hydrogels and we demonstrate the possible tuning of their properties by varying their degree of modification (DOM) and the Tz/Nb ratio (R). The percentage DOM of the gelatin derivatives was tuned between 5 and 15%. Hydrogels prepared with higher DOM cross-linked faster (i.e., 10-20 min) compared to hydrogels prepared with lower DOM (i.e., 60-70 min). A higher DOM and equimolar Tz/Nb ratio R resulted in hydrogels with lower weight variation after immersion in PBS at 37 °C. The mechanical properties of the hydrogels were tuned by varying DOM and R by 1 order of magnitude, achieving elastic modulus E values ranging from 0.5 (low DOM and nonequimolar Tz/Nb ratio) to 5 kPa (high DOM and equimolar Tz/Nb ratio). Human dental pulp stem cells were embedded in the hydrogels and successfully 3D cultured in the hydrogels (percentage viable cells >85%). An increase in metabolic activity and a more elongated cell morphology was detected for cells cultured in hydrogels with lower mechanical properties (E < 1 kPa). Hydrogels prepared with an excess of Tz or Nb were successfully adhered and remained in contact during in vitro cultures, highlighting the potential use of these hydrogels as compartmentalized coculture systems. The successful tuning of the gelatin hydrogel properties here developed by controlling their bioorthogonal cross-linking is promising for tissue engineering and in vitro modeling applications.

Advances and trends of hydrogel therapy platform in localized tumor treatment: A review

Due to limitations of treatment and the stubbornness of infiltrative tumor cells, the outcome of conventional antitumor treatment is often compromised by a variety of factors, including severe side effects, unexpected recurrence, and massive tissue loss during the treatment. Hydrogel-based therapy is becoming a promising option of cancer treatment, because of its controllability, biocompatibility, high drug loading, prolonged drug release, and specific stimuli-sensitivity. Hydrogel-based therapy has good malleability and can reach some areas that cannot be easily touched by surgeons. Furthermore, hydrogel can be used not only as a carrier for tumor treatment agents, but also as a scaffold for tissue repair. In this review, we presented the latest researches in hydrogel applications of localized tumor therapy and highlighted the recent progress of hydrogel-based therapy in preventing postoperative tumor recurrence and improving tissue repair, thus proposing a new trend of hydrogel-based technology in localized tumor therapy. And this review aims to provide a novel reference and inspire thoughts for a more accurate and individualized cancer treatment.

Microfluidic lumen-based systems for advancing tubular organ modeling

Microfluidic lumen-based systems are microscale models that recapitulate the anatomy and physiology of tubular organs. These technologies can mimic human pathophysiology and predict drug response, having profound implications for drug discovery and development. Herein, we review progress in the development of microfluidic lumen-based models from the 2000s to the present. The core of the review discusses models for mimicking blood vessels, the respiratory tract, the gastrointestinal tract, renal tubules, and liver sinusoids, and their application to modeling organ-specific diseases. We also highlight emerging application areas, such as the lymphatic system, and close the review discussing potential future directions.

Synthetic alternatives to Matrigel

Matrigel, a basement-membrane matrix extracted from Engelbreth-Holm-Swarm mouse sarcomas, has been used for more than four decades for a myriad of cell culture applications. However, Matrigel is limited in its applicability to cellular biology, therapeutic cell manufacturing and drug discovery owing to its complex, ill-defined and variable composition. Variations in the mechanical and biochemical properties within a single batch of Matrigel - and between batches - have led to uncertainty in cell culture experiments and a lack of reproducibility. Moreover, Matrigel is not conducive to physical or biochemical manipulation, making it difficult to fine-tune the matrix to promote intended cell behaviours and achieve specific biological outcomes. Recent advances in synthetic scaffolds have led to the development of xenogenic-free, chemically defined, highly tunable and reproducible alternatives. In this Review, we assess the applications of Matrigel in cell culture, regenerative medicine and organoid assembly, detailing the limitations of Matrigel and highlighting synthetic scaffold alternatives that have shown equivalent or superior results. Additionally, we discuss the hurdles that are limiting a full transition from Matrigel to synthetic scaffolds and provide a brief perspective on the future directions of synthetic scaffolds for cell culture applications.