Biosilk
Biosilk
Biosilk is a recombinant 3D culture matrix that can be biofunctionalized with tissue-specific Biolaminin isoforms to create long-term organoids.
Biosilk is a recombinant 3D culture matrix that self-assembles into an elastic microfiber network, supporting the development and long-term culture of diverse cell types. To create a biologically relevant 3D microenvironment, Biosilk can be biofunctionalized with tissue-specific Biolaminin isoforms, thereby enhancing cell viability and guiding differentiation toward the desired target cell.
Biosilk+Biolaminin microfiber networks generate long-term tissue-specific 3D microenvironment
A) Ventral midbrain organoid after 6 months showing no necrotic core, and (B) neural rosettes after 20 days in Biosilk + LN111 [Fiorenzano et al., 2021; Sozzi et al., 2022].
(C) Primary ovarian somatic cells cultured for 42 day, and (D) polyhormonal stem cell-derived pancreatic islet integrated into Biosilk 6 weeks after in vivo transplantation [Di Nisio et al., 2025; Blust et al., 2024].
A defined and long-term 3D organoid culture system
The combination of Biosilk and Biolaminin delivers a highly controlled 3D microenvironment that reduces batch‐to‐batch and intra-culture variation, supports long-term differentiation protocols, provides physiologically relevant cell–matrix and cell–cell interactions, and enables generation of organoid models with improved organization and functional maturity. It therefore provides a robust platform for disease modelling, drug discovery, regenerative medicine, and advanced cell-therapy applications.
Key benefits of Biosilk
Biorelevant 3D microenvironment
Combining Biosilk with tissue-specific Biolaminin creates a defined network that closely mimics the natural cellular niche, supporting optimal attachment, survival, and lineage-specific differentiation.
Long-term culture support
The microfiber network enables efficient nutrient and oxygen diffusion, allowing long-term stability and maturation of organoids without compromising cell viability.
Defined and animal-origin free
Chemically defined, recombinant, biodegradable, and non-immunogenic, Biosilk and Biolaminin are animal-origin free, providing a consistent matrix for research and translational applications
Reduced variability
Biosilk promotes uniform cell integration and organization, reducing batch-to-batch and intra-organoid variation compared with conventional organoid systems
No necrotic cores
Enhanced diffusion and 3D architecture prevent formation of necrotic centers, even in large organoids, supporting healthier, fully functional tissue models.
Versatile and easy to use
Biosilk forms 3D microfiber networks without special equipment and, combined with any Biolaminin isoform, creates customized microenvironments that support multiple cell types and enable long-term differentiation with multiple protocols available.
Recommended applications
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Pluripotent stem cells
Biorelevant culture of human ES and iPS cells on Biolaminin substrates Biolaminin 521 successfully replicates the genuine human stem cell niche in […] -
Intestinal cells
Biorelevant culture of intestinal cells on Biolaminin substrates Laminin expression in the intestine The small intestine contains mucosal epithelia […] -
Neural cells
Biorelevant culture of neural cells on Biolaminin substrates Laminins are widely expressed in the nervous system and are essential for the developme […] -
Hepatocytes and hepatoblasts
Biorelevant culture of liver cells on Biolaminin substrates Several laminins play a vital role in liver progenitor cell-mediated regeneration The li […] -
Lung cells
Biorelevant culture of lung cells on Biolaminin substrates Laminin expression in lung Laminin is key proteins in the basement membranes of the ai […] -
Eye cells
Biorelevant culture of eye cells on full-length laminin-521 Laminin proteins are integral components in the eye microenvironment Biolaminin products […]
Key features
The microfiber architecture of Biosilk combined with Biolaminin allows oxygen, nutrients, and patterning factors to freely diffuse throughout the 3D network. Unlike encapsulated systems, cells are directly integrated into the microfibers, enabling even cell integration, high proliferation, and long-term differentiation protocols. This supports the generation of larger organoids with uniform cellular specialization and organization, without the risk of necrotic cores.
Biosilk and Biolaminin are chemically defined, animal-origin-free matrices, ensuring consistent performance and eliminating variability associated with animal-derived substrates. This defined composition enables reproducible cell expansion, differentiation, and organoid formation, providing a reliable platform for both basic research and translational studies where experimental standardization are crucial.
Biosilk biofunctionalized with Biolaminin mimics the native extracellular matrix, creating a tissue-like microenvironment. This enhances integrin-mediated attachment, promotes physiological cell morphology, and increases experimental and preclinical relevance.
The combination of Biosilk and Biolaminin is fully biocompatible and non-immunogenic and has been shown to support vascularization and tissue remodeling in preclinical models. Its non-immunogenic properties further make it a safe platform for translational applications.
The functional and mechanical properties of Biosilk combined with Biolaminin allow for integration, expansion, and long-term differentiation of a wide range of cell types, including hPSCs, MSCs, and neural, pancreatic, and skin progenitors. By selecting the appropriate tissue-specific Biolaminin isoform for each application (e.g. LN521 for hPSCs culture), the network can be tailored to provide an optimal microenvironment, making it a versatile platform for disease modeling, drug discovery, and translational medicine.
Biosilk with Biolaminin provides a biologically relevant 3D microfiber network that mimics the native cellular niche and extracellular matrix, where cells attach to fibers, elongate, and establish defined focal adhesion points. The mild assembly process enables immediate and even integration of cells, promoting physiologically relevant cell–cell contacts and network formation, which enhances self-organization and morphogenesis. These interactions are critical for accurate modeling of in vivo cell behavior in long-term cultures.
Low inter- and intra- organoid variability in Biosilk 111 ventral midbrain organoids
Biosilk + LN111 (Biosilk 111) organoids show more uniform cell clustering and a higher proportion of dopaminergic neurons compared with conventional (Matrigel) ventral midbrain organoids at one month [Fiorenzano et al., 2021].
Biosilk 111 microfiber networks drive more uniform, mature human cerebral organoids
At day 20, Biosilk 111 cerebral organoids show overall less variability in expression patterns as well as stronger neuroectoderm marker expression, and reduced pluripotency compared with non-silk (Matrigel) organoids, highlighting more focused neural development [Sozzi et al., 2022].
No necrotic core after 6 months of culture, enabling clearer dopaminergic neuron development
Over extended culture periods, the silk microfiber network prevents necrotic core formation, supports sustained cell survival, and enables progressive maturation and diversification of dopaminergic neurons in midbrain organoids on Biosilk 111 [Fiorenzano et al., 2021].
Biosilk 111 microfiber network reduces critical cell stress pathways
Biosilk 111 microfiber networks significantly lower the expression of apoptotic pathways, reducing cell death and promoting healthier, more uniformly mature human brain organoids [Sozzi et al., 2022].
Biosilk enabled realistic 3D human ovaroids with native cell diversity
Biosilk microfiber networks generated from primary ovarian cells (cortex and medulla) after 42 days enable long-term 3D ovarian models that maintain realistic proportions of key somatic cell types [Di Nisio et al., 2025].
Development of complex multicellular cancer organoids
Biosilk networks allow for tumor-like microenvironments, as shown by co-culture of breast cancer cells (MCF-7) and primary cancer-associated fibroblasts [unpublished].
Variety of cells cultured on Biosilk
Biosilk and niche-specific Biolaminin microfiber networks can be used to grow a wide variety of primary cells and cell lines. Numerous publications demonstrate their versatility across different cell types and applications. For guidance and technical support. We are happy to provide publications and advice to help you get the most out of your 3D cultures
Protocol overview: Create attached or free-floating Biosilk+Biolaminin microfiber networks
A 3D foam structure can easily be generated by the gentle introduction of air bubbles into the Biosilk solution. The cell suspension is mixed into the foam, and the silk with cells assembles into a thin film around each bubble. The bubbles disperse and the foam transforms into a stabilized 3D network with uniformly integrated cells between the microfibers.
Pipetting introduces air bubbles to form dense foams with cells which disperse over the course of 3 days
How to generate attached Biosilk microfiber networks in 24-wells – detailed instructions
Product name
Biosilk
Product code
BS-0101
Declaration
For research use or non-commercial manufacturing of cell, gene, or tissue-based products
Storage
-80°C
Stock concentration
3 mg/ml
Appearance
Clear, colorless
Shipping condition
Dry Ice
Stability
24 months
Product description
Recombinant spider silk protein for 3D culture applications
Classification
Defined and animal origin-free, human recombinant protein
Product application
Human PSC expansion and differentiation
Assembly of FN-silk with laminin-521 to integrate hPSCs into a three-dimensional culture for neural differentiation
Åstrand C, Chotteau V, Falk A, Hedhammar M.
Biomater Sci, 2020
Fiorenzano A, Sozzi E, Birtele M, Kajtez J, Giacomoni J, Nilsson F, Andreas Bruzelius A, Sharma Y, Zhang Y, Mattsson B, Emnéus J, Rylander Ottosson D, Storm P, Parmar M
Nature Communications, 2021
Silk networking drives self-assembly of functional and mature human brain organoids
Sozzi E, Kajtez J, Bruzelius A, Wesseler MF, Nilsson F, Birtele M, Larsen NB, Rylander Ottosson D, Storm P, Parmar M, Fiorenzano A
Front. Cell Dev. Biol., 2022
Silk-Ovarioids: establishment and characterization of a human ovarian primary cell 3D-model system | Human Reproduction Open | Oxford Academic
Di Nisio V , Li T, Xiao Z, Papaikonomou K, Damdimopoulos A, Végvári A, Lebre F, Alfaro-Moreno E, Pedersen M, Svingen T, Zubarev R, Acharya G, Damdimopoulou P, Salumets A
Human Reproduction Open, 2025
Astrid Källén A, Taebnia N, Widhe M, Lauschke V.M, Hedhammar M
Biotechnology and Bioengineering, 2025
Assembly of functionalized silk together with cells to obtain proliferative 3D cultures integrated in a network of ECM-like microfibers
Johansson U, Widhe M, Shalaly ND, Arregui IL, Nilebäck L, Tasiopoulos CP, Åstrand C, Berggren PO, Gasser C, Hedhammar M.
Scientific reports, 2019
Biological responses to spider silk-antibiotic fusion protein
Gomes S, Gallego-Llamas J, Leonor IB, Mano JF, Reis RL, Kaplan DL.
J Tissue Eng Regen Med, 2017