Development and Analytical Validation of a Surface-Enhanced Raman Scattering Paper Lateral Flow Immunoassay for Detection of the Ubiquitin C-Terminal Hydrolase-L1 Traumatic Brain Injury Biomarker.

Paper lateral flow immunoassays combined with surface-enhanced Raman scattering (SERS) technology have gained increasing attention due to their high sensitivity characteristics resulting from the amplified SERS signals of the plasmon-enhanced optical probes. In contrast to conventional colorimetric lateral flow strips, SERS paper lateral flow strips (SERS-PLFSs) are currently not commercially available for widespread use. Analytical validation is the key step for commercialization.

Plasmonic silver and gold nanoparticles: shape- and structure-modulated plasmonic functionality for point-of-caring sensing, bio-imaging and medical therapy.

Silver and gold nanoparticles have found extensive biomedical applications due to their strong localized surface plasmon resonance (LSPR) and intriguing plasmonic properties. This review article focuses on the correlation among particle geometry, plasmon properties and biomedical applications. It discusses how particle shape and size are tailored controllable synthetic approaches, and how plasmonic properties are tuned by particle shape and size, which are embodied by nanospheres, nanorods, nanocubes, nanocages, nanostars and core-shell composites.

Macroporous Silk Nanofiber Cryogels with Tunable Properties.

Cryogels are widely used in tissue regeneration due to their porous structures and friendly hydrogel performance. Silk-based cryogels were developed but failed to exhibit desirable tunable properties to adapt various biomedical applications. Here, amorphous short silk nanofibers (SSFs) were introduced to fabricate silk cryogels with versatile cues.

Visible-light and near-infrared fluorescence and surface-enhanced Raman scattering point-of-care sensing and bio-imaging: a review.

This review article deals with the concepts, principles and applications of visible-light and near-infrared (NIR) fluorescence and surface-enhanced Raman scattering (SERS) in point-of-care testing (POCT) and bio-imaging. It has discussed how to utilize the biological transparency windows to improve the penetration depth and signal-to-noise ratio, and how to use surface plasmon resonance (SPR) to amplify fluorescence and SERS signals. This article has highlighted some plasmonic fluorescence and SERS probes.

Blastocyst-Inspired Hydrogels to Maintain Undifferentiation of Mouse Embryonic Stem Cells.

Stem cell fate is determined by specific niches that provide multiple physical, chemical, and biological cues. However, the hierarchy or cascade of impact of these cues remains elusive due to their spatiotemporal complexity. Here, anisotropic silk protein nanofiber-based hydrogels with suitable cell adhesion capacity are developed to mimic the physical microenvironment inside the blastocele.

Microfluidic Silk Fibers with Aligned Hierarchical Microstructures.

The hierarchical structure of the ECM provides specific niches for tissues to regulate cell behavior, yet the challenge remains to design biomaterial systems for tissue regeneration to recreate such features in vitro. Here, we achieved this goal through the use of aligned hierarchical structures of native silk fibers, generated through the integration of "bottom-up" and "top-down" strategies to generate regenerated silk fibers with aligned nano- to micro-hierarchical structures. To achieve these designs, we assembled and dispersed silk nanofibers (SNF) in formic acid and spun them into fibers using bioinspired microfluidic chips with a geometry mimicking the native silk gland.

Heparin mimics and fibroblast growth factor-2 fabricated nanogold composite in promoting neural differentiation of mouse embryonic stem cells.

The replacement therapy or transplantation using neural cells, which differentiated from stem cells, has emerged as a promising strategy for repairing damaged neural tissues and helping functional recovery in the treatment of neural system diseases. The challenge, however, is how to control embryonic stem cell fate so that neural differentiation can be efficiently directed to enrich a neuron cell population, and meanwhile to maintain their bioactivities. This is a key question and has a very significant impact in regenerative medicine.

Dual Pathway for Promotion of Stem Cell Neural Differentiation Mediated by Gold Nanocomposites.

The neural differentiation of embryonic stem cells (ESCs) is of great value in the treatment of neurodegenerative diseases. On the basis of the two related signaling pathways that direct the neural differentiation of ESCs, we used gold nanoparticles (GNP) as a means of combining chemical and physical cues to trigger the neurogenic differentiation of stem cells. Neural differentiation-related functional units (glyco and sulfonate units on glycosaminoglycans, GAG) were anchored on the GNP surface and were then transferred to the cell membrane surface via GNP-membrane interactions.

Modular Polymers as a Platform for Cell Surface Engineering: Promoting Neural Differentiation and Enhancing the Immune Response.

Regulating cell behavior and cell fate are of great significance for basic biological research and cell therapy. Carbohydrates, as the key biomacromolecules, play a crucial role in regulating cell behavior. Herein, "modular" glycopolymers were synthesized by reversible addition-fragmentation chain transfer polymerization.

Structure-Chemical Modification Relationships with Silk Materials.

Chemical modifications used with silk materials can be challenging due to heterogeneous reactions, in part due to the assembly state of the protein chains. Here, we assess factors that determine the efficiency of chemical modifications with silk materials. Unlike other natural macromolecules, silk presents changeable self-assembled or aggregation states in aqueous solution, which affect the chemical reactions based on reactive group distribution or accessibility.

Small addition of Zn in Ca@DNA results in elevated gene transfection by aminated PGMA-modified silicon nanowire arrays.

Gene therapy, a promising and effective treatment, has ignited new hope in overcoming difficult-to-cure diseases. The key question in gene therapy is how to efficiently and safely deliver exogenous nucleic acids into the nuclei of target cells. To achieve stable, efficient and safe gene transfer and to ensure efficiency of gene transfer into cell nuclei, a zinc ion-assisted gene delivery nanosystem was proposed in the present study by loading a low concentration of Zn in Ca@DNA nanoparticles on ethanolamine-functionalized poly(glycidyl methacrylate) (PGEA)-modified SiNWAs (Zn/Ca@DNA + SN-PGEA).

Microfluidic channels with renewable and switchable biological functionalities based on host-guest interactions.

Poly(dimethylsiloxane) (PDMS)-based microfluidic systems are gaining increasing attention due to their ease of fabrication, optical transparency and mechanical properties. However, the inherent hydrophobicity and chemical inertness of PDMS hinder its wider application in microfluidic systems. There is thus a strong need for methods for surface modification of PDMS-based microfluidic channels.