Scaffold-based developmental tissue engineering strategies for ectodermal organ regeneration

Abstract

Tissue engineering (TE) is a multidisciplinary research field aiming at the regeneration, restoration, or replacement of damaged tissues and organs. Classical TE approaches combine scaffolds, cells and soluble factors to fabricate constructs mimicking the native tissue to be regenerated. However, to date, limited success in clinical translations has been achieved by classical TE approaches, because of the lack of satisfactory biomorphological and biofunctional features of the obtained constructs. Developmental TE has emerged as a novel TE paradigm to obtain tissues and organs with correct biomorphology and biofunctionality by mimicking the morphogenetic processes leading to the tissue/organ generation in the embryo. Ectodermal appendages, for instance, develop in vivo by sequential interactions between epithelium and mesenchyme, in a process known as secondary induction. A fine artificial replication of these complex interactions can potentially lead to the fabrication of the tissues/organs to be regenerated. Successful developmental TE applications have been reported, in vitro and in vivo , for ectodermal appendages such as teeth, hair follicles and glands. Developmental TE strategies require an accurate selection of cell sources, scaffolds and cell culture configurations to allow for the correct replication of the in vivo morphogenetic cues. Herein, we describe and discuss the emergence of this TE paradigm by reviewing the achievements obtained so far in developmental TE 3D scaffolds for teeth, hair follicles, and salivary and lacrimal glands, with particular focus on the selection of biomaterials and cell culture configurations.

Electrostatically optimized adapalene-loaded emulsion for the treatment of acne vulgaris

“…Next, we evaluated the ability of the AD emulsions containing the cationic MC-[NH 2 ] x emulsifier to deliver AD into the dermis through the epidermis via topical application. The lipid lamellae of the stratum corneum contain a high proportion of negatively charged lipids, and therefore the skin acts as a negatively charged membrane [ 30 , 31 ]. Thus, the positively charged MC-[NH 2 ] x emulsifier may facilitate the absorption of AD through the skin membrane.…”

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

“…As the prepared hydrogels displayed promising characteristics as a 3D biomimetic ECM for in vitro cell culture, we further investigated the possibility of creating more complex hydrogel constructs by chemically coupling gelatin hydrogels. Hydrogels loaded with different cell populations and put in contact one with one another might allow, in the future, for compartmentalized cell coculture, which could be useful for complex tissue regeneration, such as in the case of epithelial-mesenchymal cell coculture for organ regeneration by mimicking embryonic morphogenesis, interface tissue engineering, and the development of in vitro 3D coculture models with compartmentalized cocultured cells . It is however necessary that such hydrogels maintain contact over the in vitro culture period to facilitate cellular processes including migration and paracrine signaling.…”

Immunomodulatory properties of mesenchymal stem cells/dental stem cells and their therapeutic applications

“…MSCs seeded on certain matrices may possess functions that are not present in MSCs in monolayer cultures and last longer in vivo. An emerging field called developmental tissue engineering mimics morphogenetic processes during development to harvest biofunctional tissues and organs [ 141 ]. These approaches can be used to generate MSC-based materials that have long-lasting immunomodulatory functions in vivo.…”