Biology subjects

De Laporte, L.

Publications and source records attributed to De Laporte, L..

7 recordsLinked to original sources

bioRxiv2026

Patterned alginate hydrogel spatially guides collagen fibrillogenesis, viscoelasticity and endothelial cell invasion

Angiogenesis following injury has been shown to be driven by fibrillar proteins of the extracellular matrix (ECM), such as collagen. However, the use of protein-based biomaterials presents some challenges, such as uncontrolled degradation and limited tuneability. We demonstrate how to create patterned interpenetrating networks (IPNs) based on covalently crosslinked alginate and physically crosslinked collagen that provide suitable mechanical properties to support migration of endothelial cells (ECs) in a spatially controlled manner. Low molecular weight alginate is functionalized with norbornene (N) or tetrazine (T), which enables two independent covalent crosslinking methods: UV-mediated and degradable crosslinks with matrix metalloproteinase (MMP) sensitive peptides (Deg) and slower spontaneous N:T non-degradable crosslinks (noDeg). Using photolithography, patterns in degradation, collagen fibrillogenesis, microarchitecture and matrix viscoelasticity are created. The potential of such 3D patterned alginate-collagen (Alg-Col) IPNs to spatially guide EC invasion and proliferation was tested in a microfluidics platform resembling an early healing setting. Only regions combining collagen fibrillogenesis, alginate degradability and viscoelasticity demonstrated EC cell invasion similar to the ones found in vivo following injury. The 3D patterned Alg-Col IPNs are compatible with microfluidics, offer an strategy to widen the applications of protein-based hydrogels and present a versatile platform for tissue engineering and disease modeling.

bioengineering↗

bioRxiv2026

Differentiation and maturation of iPSC-derived motor and sensory neurospheres using biomodified PEG-based microgels

Sensory and motor neurons differ significantly in their morphology, structural organization, functional properties, and mode of action. However, despite this heterogeneity, many in vitro studies focus only on a single neuronal subtype, mainly being sensory neurons, limiting the translational potential and relevance of these studies for the evaluation of therapeutic options for spinal cord injury. In this study, we investigate the differentiation, maturation, and neuronal outgrowth of human induced pluripotent stem cell (iPSC)-derived motor and sensory neurospheres using polyethylene glycol (PEG)-microgels with various bioactive coatings. Our results show subtype-specific responses to the PEG-microgel scaffolds, with respect to motor and sensory neurosphere morphology and size. Furthermore, we compare the formation of the PEG-microgel/scaffolds when starting from iPSCs-derived precursor neuron spheres versus undifferentiated iPSCs. We observe notable differences in structural organization, maturity, and neuronal outgrowth between the two approaches, as well as between motor and sensory neurospheres. Together, these results underline the importance of studying motor and sensory neurons separately and highlight the need for a controlled, tunable culture platform to assess the impact of the microenvironment and to improve the physiological relevance of in vitro platforms for neuron-based research.

bioengineering↗

bioRxiv2026

Effects of MRI on an Injectable Hydrogel with Magnetically Alignable Microstructures for Oriented Cell Growth

Injectable biomaterials with aligned microstructures play a critical role in tissue engineering and drug-delivery applications where control over the position and orientation of cells and nano/micron-scale architectures enhance intervention efficacy. Patients are often subject to MRI scans; for patient safety and treatment efficacy, we investigated the effects of MRI on a biomaterial treatment consisting of aligned magnetic microstructures being developed for guiding cell growth. Under MRI exposure, potential movement of aligned structures could be detrimental to nearby cells, and potential MRI-induced heating could adversely affect traumatized tissue. In this work, the alignment state and heat conduction of such a treatment were studied using a 9.4 T preclinical MRI. The treatment comprises short magnetic rod-shaped polycaprolactone fibers (rods) with embedded magnetic nanoparticles in a surrounding hydrogel (gelatin methacrylate), with rod alignment observed before and after a 45-minute MRI scan. No change in rod alignment state was observed, and no heat generation was measured. A theoretical framework was developed which supports the experimental observation that the biomaterial is stable under MRI. This work can be extended to other biomaterial systems with aligned architectures used in tissue engineering applications such as spinal cord, muscle and tendon.

bioengineering↗

bioRxiv2025

Structural guidance in 3D microgel-in-hydrogel systems to improve chondrogenesis

Anisotropic biomaterials are broadly studied in regenerative medicine as they aim to mimic the hierarchical structures of native tissue. The Anisogel, an anisotropic microgel-in-hydrogel system, involves two key factors for tissue engineering: guidance cues - magnetically aligned rod-shape structures - and a surrounding matrix - polyethylene glycol-vinylsulfone (PEG-VS) with a degradable peptide crosslinker. This research shows the potential of using a PEG-VS-based Anisogel to allow for guided ingrowth and chondrogenic differentiation of human mesenchymal stromal cells (hMSCs) modulated by the alignment and size of anisometric microgels. The properties of the surrounding matrix are optimized for the availability of anchoring peptides (RGD concentration) and matrix density (hydrogel precursor concentration). The microgels of highest tested dimensions (10x10x100 {micro}m3) lead to a donor-independent significant upregulation of chondrogenic markers (SOX 9, ACAN and COL2AI) and a decrease of hypertrophic chondrogenic markers (RUNX 2), compared to unaligned and smaller microgel sizes. As a proof of concept, the Anisogel is tested in a semi-orthotopic mouse model where the effect of microgel alignment on cell infiltration and osteochondral tissue formation is evaluated.

bioengineering↗

bioRxiv2025

Fabrication of Short Polymeric μFibers as Building Blocks for Anisotropic High-Throughput Compatible 3D Tissue Models

Modeling the 3D microenvironment and cell growth of natively anisotropic human tissues in vitro constitutes a significant challenge in tissue engineering and biofabrication. Short polymeric fibers gain growing attention in this field due to their applicability as pipettable or injectable anisometric building blocks in 3D hydrogel-based cell culture systems or bioinks. However, the production of monodisperse short fibers with high production rates suitable for screening remains challenging. In this study, short, quasi-monodisperse, magneto-responsive, fluorescent poly({varepsilon}-caprolactone) {micro}fibers with variable dimensions in the micrometer range are produced in a scalable, semi-continuous two-step fabrication process combining controlled wet-dry spinning with subsequent cryosectioning. Influences of the spinning process parameters on fiber properties and process features, as well as boundary spinning conditions and upscaling potential, are explored using Design of Experiments approaches. Further, magnetic alignment of the {micro}fibers in a weak magnetic field and incorporation of nile red as fluorescent dye for facile analysis in 3D are demonstrated. Implementation of aligned {micro}fibers into a hydrogel-based 3D vasculogenesis model, produced in a high-throughput automated manner, is shown to stimulate oriented cell growth. This highlights the potential of our {micro}fibers as guiding elements inside tissue and disease models and their suitability for automated high-throughput applications.

bioengineering↗

bioRxiv2025

Microgels enable iPSCs to assemble, expand, and differentiate into organoids -- from sizable to high throughput

Organoid research holds tremendous potential for personalized medicine and drug development. However, current limitations include reproducibility issues largely due to the use of biologically derived materials, which are prone to batch-to-batch variations. Here, we report a new technology for human induced pluripotent stem cell (iPSC)-based organoid production with iPSC expansion and differentiation in the same construct in a reproducible and scalable manner, compatible with high-throughput automation. Chemically defined poly(ethylene glycol) (PEG)-based microgels are produced via parallelized step-emulsification microfluidics, enabling scalable production. This approach leverages the self-organization of iPSCs with microgels to build three-dimensional constructs, driven by robust cell-material interactions achieved through vitronectin-coated PEG microgels. This technology allows the iPSCs to expand and retain their pluripotency, after which they can be differentiated into the three germ layers, providing a suitable platform for organoid differentiation. This was further extended by differentiation into cardiac organoids and retinal photoreceptors to demonstrate two exemplary tissues.

bioengineering↗

bioRxiv2025

Photodegradable Hydrogels for On-Demand Modeling of Age-Related Spatiotemporal ECM Deformation

The extracellular matrix (ECM) plays a crucial role in regulating tissue behavior through a dynamic interplay of spatial and temporal cues. Dynamic materials capable of modulating these cues at relevant scales are essential for tackling current challenges in tissue engineering and addressing fundamental biological questions. In vision research, there is a notable lack of suitable in vitro systems to study ECM dynamics. To help fill this gap, we developed an easy-to-use, photosensitive poly(ethylene glycol)-based hydrogel that can deform on demand to simulate ECM bulging, known as drusen, associated with the aging of the outer retina. Our findings demonstrate that variations in the size of these artificial drusen during culture impact morphometric parameters of the retinal pigment epithelium, offering new insights into its mechanical resilience to different drusen sizes. Notably, drusen formation in our system does not significantly affect the cellular actin cytoskeleton or polarity, which are often disrupted in conventional acute substrate deformation models, allowing the study of early aging before detectable pathology. In summary, we present a light-tunable hydrogel platform that enables precise spatial mimicry of ECM topographical changes, offering a promising tool for investigating the mechanobiological aspects of dynamic cell-matrix interactions.

bioengineering↗