Xeno-Free 3D Bioprinted Liver Model for Hepatotoxicity Assessment.

Three-dimensional (3D) bioprinting is one of the most promising methodologies that are currently in development for the replacement of animal experiments. Bioprinting and most alternative technologies rely on animal-derived materials, which compromises the intent of animal welfare and results in the generation of chimeric systems of limited value. The current study therefore presents the first bioprinted liver model that is entirely void of animal-derived constituents.

Advances in Animal Models and Cutting-Edge Research in Alternatives: Proceedings of the Third International Conference on 3Rs Research and Progress, Vishakhapatnam, 2022.

Animal experimentation has been integral to drug discovery and development and safety assessment for many years, since it provides insights into the mechanisms of drug efficacy and toxicity (e.g. pharmacology, pharmacokinetics and pharmacodynamics).

Frequently Used Strategies to Isolate Extracellular Matrix Proteins from Human Placenta and Adipose Tissue.

The natural extracellular matrix (ECM) provides the optimal environment for cells. Many enzymatic or non-enzymatic based strategies to extract ECM proteins from tissues were published over the past years. However, every single isolation strategy reported so far is associated with specific bottlenecks.

Novel Human Placenta-Based Extract for Vascularization Strategies in Tissue Engineering.

There is critical unmet need for new vascularized tissues to support or replace injured tissues and organs. Various synthetic and natural materials were already established for use of two-dimensional (2D) and three-dimensional (3D) neovascularization assays, however, they still cannot mimic the complex functions of the sum of the extracellular matrix (ECM) in native intact tissue. Currently, this issue is only addressed by artificial products such as Matrigel, which comprises a complex mixture of ECM proteins, extracted from animal tumor tissue.

Microvascular effects of microneedles with subsequent histamin application in the skin prick test.

Background: Since decades, histamin applications are routinely performed in skin prick tests using a lancet. However, this technique is associated with various drawbacks.

Materials And Methods: In healthy human subjects, we investigated the effects of microneedle-enhanced histamin delivery (wheal size, erythema size) in the skin microvasculature using polarized light spectroscopy imaging (Tissue Viability imaging, TiVi).

Microvascular effects of microneedle application.

Background: The efficiency of transdermal drug delivery may be increased by pretreating the skin with microneedles, but distinct effects of microneedles and the microneedle-enhanced delivery of vasoactive drugs on the skin microvasculature are still not well investigated.

Materials And Methods: In eight healthy human subjects, we measured the microvascular response to microneedle-induced microtraumas in the skin microvasculature using polarized light spectroscopy imaging (Tissue Viability imaging, TiVi). The microvascular response was assessed for up to 48 hours for three microneedle sizes (300 µm, 500 µm, and 750 µm) and for different pressures and application times.

Human Placenta Laminin-111 as a Multifunctional Protein for Tissue Engineering and Regenerative Medicine.

Laminins are major components of all basement membranes surrounding nerve or vascular tissues. In particular laminin-111, the prototype of the family, facilitates a large spectrum of fundamental cellular responses in all eukaryotic cells. Laminin-111 is a biomaterial frequently used in research, however it is primarily isolated from non-human origin or produced with time-intensive recombinant techniques at low yield.

An Effective Method of Atelocollagen Type 1/3 Isolation from Human Placenta and Its In Vitro Characterization in Two-Dimesional and Three-Dimensional Cell Culture Applications.

Pepsin-solubilized atelocollagen can be used to form highly complex three-dimensional matrices for a broad spectrum of tissue engineering applications. Moreover, it has a long history as a favorable biomaterial in pharmaceutical and medical industries. So far, the main sources for these approaches are collagens from xenogenic sources.

Covalent binding of placental derived proteins to silk fibroin improves schwann cell adhesion and proliferation.

Schwann cells play a key role in peripheral nerve regeneration. Failure in sufficient formation of Büngner bands due to impaired Schwann cell proliferation has significant effects on the functional outcome after regeneration. Therefore, the growth substrate for Schwann cells should be considered with highest priority in any peripheral nerve tissue engineering approach.

Modeling Perfusion Dynamics in the Skin During Iontophoresis of Vasoactive Drugs Using Single-Pulse and Multiple-Pulse Protocols.

Objective: After iontophoresis of vasoactive drugs into the skin, a decrease in perfusion is commonly observed. We delivered vaso-active drugs by iontophoresis using different delivery protocols to study how these affect this decrease in perfusion as measured using LDF.

Methods: We measured skin perfusion during iontophoresis of (ACh), MCh, and NA using a single pulse or separate pulses at different skin sites, and during repeated delivery of ACh at the same site.