Regenerating Hair in Prevascularized Tissue Space Formed by a Controllable Foreign Body Reaction

Abstract

Intracutaneous transplantation of trichogenic cells is a currently endorsed strategy to realize hair regeneration in vivo. However, skin is not the most advantageous transplant site due to the robust mechanical property and deficient physiological perfusion. Herein, a subcutaneous space made of prevascularized collagen fibers (PVCF) generated by controlling the duration of in situ foreign body reaction is reported. In contrast to skin, an optimally preprogrammed PVCF presents a larger tissue volume (171 mm3), low Young's modulus (1/2‐fold), high flexibility high mechanical energy dissipation rate (1.3‐fold), highly permeable surface structure, and plentiful vascular network. Remarkably, cells transplanted into PVCF suffer less apoptosis and necrosis, and generate more mature hairs (≈289 per site) than that in intracutaneous transplantation (≈177 per site). The RNA‐sequencing profiling indicates similar trends under molecular level. This work provides a promising strategy to improve graft site microenvironment physiologically and mechanically, with a low‐cost and simple fabrication process.

Scalable and high-throughput production of an injectable platelet-rich plasma (PRP)/cell-laden microcarrier/hydrogel composite system for hair follicle tissue engineering

“…Although we achieved HF induction, the center of the spheroids continued to become hypoxic. Moreover, although pre-vascularized collagen fibers, formed via foreign body reaction [35], and pre-vascularized layerby-layer microtissues [11] enhance blood perfusion in regenerative tissues, they require complex and relatively inefficient preparation processes. In contrast, a 3D-bioprinted scaffold [36] can better simulate the HF microenvironment, however, is incapable of simulating the associated macroenvironment.…”

Construction of high-performance circularly polarized multiple-resonance thermally activated delayed fluorescence materials via the structural optimization of peripheral groups

“…Generally, CP-MR-TADF materials are designed by integrating the opposite multiple resonance effects of electron-deficient and electron-donating atoms/groups and chirality characters (axial, helical, central and planar chirality) in one molecular framework to achieve desirable CPL properties and narrowband emissions with high quantum efficiency. [6][7][8][9][10][11][12][13][14] The multiple resonance effects induced by the separated frontier molecular orbital (FMO) distributions on the adjacent atoms/groups generally cause a relatively large FMO wave function overlap and thus a larger transition electric dipole moment (m) to maintain a narrowband emission with high quantum efficiency; [15][16][17][18][19][20][21] however, the increased m value would inevitably result in the decreased g value according to the equation g ¼ 4jmjjmj cos y jmj 2 þ jmj 2 ffi 4jmj cos y jmj , where m represents the transition magnetic dipole moment and y m,m is the angle between m and m. Therefore, how to increase the g value and balance the contradictory requirements of high quantum efficiency and g value is the key in developing high-performance CP-MR-TADF materials.…”

Marching Toward Long‐Wavelength Narrowband Emissive Multi‐Resonance Delayed Fluorescence Emitters for Organic Light Emitting Diodes

“…However, due to the atomically separated HOMO and LUMO orbitals, the MR‐TADF emitters possess feeble CT character, hence it is highly challenging to realize bathochromic shifted emission from blue‐green region. [ 51–149 ] However, the long‐wavelength ( λ em > 550 nm) MR‐TADF emitters with narrow FWHM are scarcely reported due to the limited scope for structural diversity, weak short range charger transfer (SRCT) and complicated synthetic procedures. [ 85–113 ] Therefore, it is urgent need to develop new emitter designs for constructing long‐wavelength MR‐TADF emitters without compromising the FWHM.…”

“…[ 51–149 ] However, the long‐wavelength ( λ em > 550 nm) MR‐TADF emitters with narrow FWHM are scarcely reported due to the limited scope for structural diversity, weak short range charger transfer (SRCT) and complicated synthetic procedures. [ 85–113 ] Therefore, it is urgent need to develop new emitter designs for constructing long‐wavelength MR‐TADF emitters without compromising the FWHM. Besides, although the conceptual advancement has been derived several MR‐TADF emitters, contrary to the conventional TADF emitters, they often possess low spin up conversion rates ( k RISC ≈ 10 4 s −1 ), which leads to the undesirable bimolecular quenching and severe efficiency roll‐off at practical brightness; this needs to be resolved from material design perspective.…”