sw1222 cell line&#45;derived colorectal cancer organoid fabrication in ultrashort self-assembling peptide matrix

Evaluación de péptidos biofuncionales autoensamblables para la adhesión y morfología celular

In recent years, self-assembling peptides (SAPs) have emerged as promising biomaterials for tissue engineering applications. SAPs possess unique properties, including spontaneous formation of nanofibers, biocompatibility, biodegradability, and non-immunogenicity, making them attractive candidates for scaffold development1. SAPs have been previously used together with various types of cells, and notably, reported ultrashort SAPs have facilitated the encapsulation of stem cells while upholding their pluripotency over prolonged periods encompassing more than 30 passages and with minimal incidence of chromosomal aberrations2,3,4. Hence, adapting SAPs for their use in organoid culture constituted a rational subsequent step.
Organoids are complex three-dimensional structures that arise from single pluripotent cells. These structures give rise to various cell types, which then self-organize to replicate the developmental processes of embryonic and tissue growth in vitro5. This innovative framework has evolved into a formidable tool for in vitro investigations, efficiently conserving the genetic, phenotypic, and behavioral attributes characteristic of in vivo organs6. Nevertheless, a principal impediment in the bench-to-bedside transition of organoid-based findings is the need for reproducibility7. This variation in results is primarily ascribed to the difficulty in fully differentiating human pluripotent stem cells into specialized cell lineages, compounded by the absence of authentic tissue architecture and the inherent complexity encountered in organoid models. Given the rise in popularity of stem-cell- and organoid-based studies8, there has been an escalated demand for biomaterials with dynamic mechanical properties and integrin-like adhesion sites or scaffolds with controlled degradability7,9. These attributes can be effectively tuned through the strategic utilization of biofunctionalized SAPs.
SAPs are short sequences of amino acids with the inherent ability to spontaneously organize into well-defined structures10. These peptides often contain alternating hydrophobic and hydrophilic residues, which drive their self-assembly through non-covalent interactions, including hydrogen bonding, electrostatic interactions, and hydrophobic effects11,12. The self-assembly process of these peptides is primarily driven by the need to minimize the system&#39;s free energy. When in an aqueous environment, the hydrophobic residues tend to cluster together to minimize their exposure to water, while the hydrophilic residues interact with the surrounding water molecules. This phenomenon leads to the formation of various nanostructures. In this case, ultrashort self-assembling peptides form nanofibers with characteristics that depend on the peptide sequence and environmental conditions2,12,13,14,15,16. These peptides adopt a &#946;-turn conformation, where individual peptide strands align parallel or antiparallel to each other, stabilized by hydrogen bonds (Figure 1). The presence of positive ions accelerates the self-assembling processes that lead to nanofiber formation.
Peptide nanofibers have been identified as possessing an innate ability to entrap significant volumes of water. This characteristic facilitates the generation of a hydrogel, which subsequently manifests as a biocompatible and biodegradable three-dimensional space conducive to cellular proliferation and growth. These self-assembling peptide nanofibers intricately emulate the topographical features inherent to the natural extracellular matrix (ECM) environment1. This resemblance endows cells with an environment that imitates their physiological habitat, further promoting optimal cellular activities17. Furthermore, the versatility inherent to these peptides permits a considerable degree of tunability4. Such adaptability enables changes to the matrix&#39;s properties, such as stiffness, gelation kinetics, and porosity. These adaptations are achieved through modifications to the peptide sequence. Consequently, self-assembling peptides (SAPs) have emerged as pivotal components in contemporary biomaterial science, extensively used as scaffolds for tissue regeneration and cellular culture13,17.
One of the critical advantages of self-assembling peptides is their ability to be easily synthesized and modified at the molecular level. This advantage allows for the incorporation of specific functional groups or bioactive motifs into the peptide sequence, enabling the design of peptides with tailored properties and functionalities18,19,20 (Figure 1B). For example, biofunctionalized SAPs can be designed to mimic the ECM and promote differentiation using the RGD peptide19,21. Peptide Ben-IKVAV has also been reported to significantly increase the expression of neuronal-specific markers due to its ligand-specific motiety22. These peptides can also be engineered to display bioactive molecules, such as integrin-binding peptides, to enhance cell survival23. Finally, other biofunctionalized SAPs have been developed to promote angiogenesis by including the IKVAV and YIGSR motifs in their structures24.
Biofunctionalized SAPs reported in an earlier publication show that self-assembling can be further modified by including the na&#239;ve peptide from which the biofunctionalized SAP was derived25. These SAP mixtures can also provide a wide array of SAP formulations that vary in their biochemical activity and physicochemical properties. For instance, the amphiphilic peptide IIFK is an ultrashort SAP that can withstand biofunctionalization with various motifs, exemplified by the incorporation of the IKVAV motif (Figure 1B). Both peptides can form nanofibers, both alone and combined. Each formulation results in hydrogels with varying physical properties (Figure 2)
However, because of the extensive array of potential permutations and alternatives obtained from the biofunctionalization of SAPs, there is a need to provide a fast and cost-effective option for organoid testing. One candidate for such intensive and cost-effective organoid evaluation is the SW1222 cell line, derived from human colorectal adenocarcinoma26,27. SW1222 cells possess characteristics that enable their aggregation into 3D structures resembling organoids, making them an ideal model for studying tissue development and regenerative medicine applications. SW1222 cells have been identified as capable of generating organoids owing to their intrinsic overexpression of the LGR5 gene27. The creation of organoids from individual LGR5+ stem cells has been convincingly exhibited before, as well as the propensity of SW1222 cells to achieve morphological characteristics of a colorectal cancer organoid28.
In this methods paper, we present detailed protocols for evaluating and characterizing the effects of various biofunctional peptides on cell adhesion and lumen formation using SW1222 cells (Figure 3). By providing step-by-step procedures and imaging analysis methods, we hope to offer valuable insights into the biofabrication of organoids and the evaluation of simplistic SAP matrices for organoid culture.

Autor destacado: Optimización de matrices de péptidos ultracortos para organoides de cáncer colorrectal

Fabricación y caracterización de organoides de cáncer colorrectal de la línea celular SW1222 en matriz de péptidos autoensamblables ultracortos

Our research aims to evaluate ultrashort self-assembling peptides as matrices for Colorectal Cancer Organoid Cultures. We address questions about organoid morphology, for viability, proliferation, and the adhesion and the impact of biofunctionalization. The goal is to optimize peptide matrix compositions for effective organoid growth, and to contribute to regenerative medicine.Cutting-edge technologies in our field involve 3D bioprinting for precise organic fabrication, microfluidic platforms for dynamic culture environments, and advanced imaging tools like atomic force microscopy and multiphoton microscopy. CRISPR-Cas9 gene editing refines genetic modification, while single cell RNA sequencing provides in-depth molecular insights. Current experimental challenges include enhancing organoid reproducability, refining vascularization for larger constructs, and mimicking complex tissue architecture.Overcoming these limitations in long-term culture and incorporating immune components into models are active areas. Achieving standardized protocols and addressing ethical concerns opposing ongoing challenges in this field. Significant findings in our field include demonstrating the suitability of ultrashort self-assembling peptides for organoid cultures.We have shown the versatility, reproducability, and stability of these peptides, providing a platform for fine tuning micro-environments. This contributes to advancing organoid-based studies, regenerative medicine, and biofunctionalized hydrogel research. Our protocol bridges and research gap, whereby providing a systematic approach to evaluating organoids in ultrashort self-assembling peptide matrices.It addresses the need for standardized methods in assessing cell behavior within these matrices, aiding in durational design of peptide-based hydrogels for optimal organoid growth and advancing regenerative medicine studies.

SW1222 Fabricación de organoides de cáncer colorrectal derivados de líneas celulares en matriz de péptidos autoensamblables ultracorta

Para comenzar, pipetee 10 gotas de microlitros de solución de péptidos 2X en el centro de los pocillos en una placa de 24 pocillos. Después de la incubación, pipetee 10 microlitros de 2X PBS en cada pocillo. Utilice la punta de la pipeta para mezclar la solución suavemente, deje que las gotas de gel se estabilicen durante al menos 20 minutos, asegurándose de que las gotas estén intactas.A continuación, pipetee 2,5 mililitros de EDTA de tripsina al 0,0125% en un matraz que contiene 2 millones de células de adenocarcinoma colorrectal humano SW1222. Incubar las células con tripsina a 37 grados centígrados durante cinco a 10 minutos hasta que se desprendan del matraz. Añadir cinco mililitros de medio completo para inactivar la tripsina.A continuación, filtre la suspensión celular con un colador de células de 30 micrómetros. Con una micropipeta de 10 microlitros, inyecte dos microlitros de la suspensión celular en cada gota de péptido. Siembre 800 células de la línea celular SW1222 en cada pocillo durante cuatro días.Incubar las gotas durante 30 minutos a 37 grados centígrados bajo un 5% de dióxido de carbono. A continuación, añada 0,5 mililitros de medio suplementado a cada pocillo. Para preparar el control, diluya el stock del control de la matriz de membrana basal con medio suplementado.Cargue la suspensión de la celda en la solución basal de membrana diluida. Pipetear 20 microlitros de matriz de membrana basal diluida en cada pocillo con las células. Incubar las células durante 20 minutos a 37 grados centígrados.Después de que las gotas se solidifiquen, agregue 0,5 mililitros de medio completo. Tome imágenes de las células utilizando un microscopio de campo claro en los días uno, cuatro y siete para evaluar el crecimiento de los organoides. Una semana, las imágenes de campo claro de las células mostraron que los pequeños grupos de células se estaban ensamblando en organoides.Los organoides derivados de SW1222 cultivados en hidrogeles peptídicos tenían una morfología redonda con un aspecto ligero. Una apariencia más oscura indicaba una densidad más alta indeseable como se observa en las colonias del péptido P en el día siete.

sw1222-cell-linederived-colorectal-cancer-organoid-fabrication

Research

JoVE Journal

Bioengineering

SW1222 Cell Line&#45;Derived Colorectal Cancer Organoid Fabrication in Ultrashort Self-Assembling Peptide Matrix

Fabrication and Characterization of Colorectal Cancer Organoids from SW1222 Cell Line in Ultrashort Self&#45;Assembling Peptide Matrix

Ultrashort self-assembling peptides (SAPs) can spontaneously form nanofibers that resemble the extracellular matrix. These fibers allow the formation of ...

Investigación

Bioingeniería

Immunostaining of Colorectal Cancer&#45;Derived Organoids in Peptide Hydrogel

Inmunotinción de organoides derivados del cáncer colorrectal en hidrogel peptídico

Imaging Immunostained Colorectal Cancer&#45;Derived Organoids in Peptide Hydrogel for Evaluating the Effects of Self&#45;Assembling Peptides on Cell Adhesion

Obtención de imágenes de organoides derivados del cáncer colorrectal inmunoteñidos en hidrogel de péptidos para evaluar los efectos de los péptidos autoensamblables en la adhesión celular