Sequential release of nanoparticle payloads from ultrasonically burstable capsules.

In many biomedical contexts ranging from chemotherapy to tissue engineering, it is beneficial to sequentially present bioactive payloads. Explicit control over the timing and dose of these presentations is highly desirable. Here, we present a capsule-based delivery system capable of rapidly releasing multiple payloads in response to ultrasonic signals.

Switchable Release of Entrapped Nanoparticles from Alginate Hydrogels.

Natural biological processes are intricately controlled by the timing and spatial distribution of various cues. To mimic this precise level of control, the physical sizes of gold nanoparticles are utilized to sterically entrap them in hydrogel materials, where they are subsequently released only in response to ultrasound. These nanoparticles can transport bioactive factors to cells and direct cell behavior on-demand.

The role of neurotrophic factors conjugated to iron oxide nanoparticles in peripheral nerve regeneration: in vitro studies.

Local delivery of neurotrophic factors is a pillar of neural repair strategies in the peripheral nervous system. The main disadvantage of the free growth factors is their short half-life of few minutes. In order to prolong their activity, we have conjugated to iron oxide nanoparticles three neurotrophic factors: nerve growth factor (βNGF), glial cell-derived neurotrophic factor (GDNF), and basic fibroblast growth factor (FGF-2).

Antibody-conjugated, dual-modal, near-infrared fluorescent iron oxide nanoparticles for antiamyloidgenic activity and specific detection of amyloid-β fibrils.

Amyloid-β (Aβ) peptide is the main fibrillar component of plaque deposits found in brains affected by Alzheimer's disease (AD) and is related to the pathogenesis of AD. Passive anti-Aβ immunotherapy has emerged as a promising approach for the therapy of AD, based on the administration of specific anti-Aβ monoclonal antibodies (aAβmAbs) to delay Aβ aggregation in the brain. However, the main disadvantage of this approach is the required readministration of the aAβmAbs at frequent intervals.

Age-dependent effects of microglial inhibition in vivo on Alzheimer's disease neuropathology using bioactive-conjugated iron oxide nanoparticles.

Background: Tau dysfunction is believed to be the primary cause of neurodegenerative disorders referred to as tauopathies, including Alzheimer's disease, Pick's disease, frontotemporal dementia and Parkinsonism. The role of microglial cells in the pathogenesis of tauopathies is still unclear. The activation of microglial cells has been correlated with neuroprotective effects through the release of neurotrophic factors and through clearance of cell debris and phagocytosis of cells with intracellular inclusions.

Magnetic scaffolds enriched with bioactive nanoparticles for tissue engineering.

Novel magnetic fibrin hydrogel scaffolds for cell implantation and tissue engineering are reported. The magnetic scaffolds are produced by the interaction between thrombin-conjugated maghemite nanoparticles of narrow size distribution and fibrinogen. These scaffolds, enriched with growth factor conjugated fluorescent maghemite nanoparticles, provide a supporting 3D environment for massive proliferation of various cell types, and can be successfully visualized by MRI.

Engineered polymer nanoparticles containing hydrophobic dipeptide for inhibition of amyloid-β fibrillation.

Protein aggregation into amyloid fibrils is implicated in the pathogenesis of many neurodegenerative diseases. Engineered nanoparticles have emerged as a potential approach to alter the kinetics of protein fibrillation process. Yet, there are only a few reports describing the use of nanoparticles for inhibition of amyloid-β 40 (Aβ(40)) peptide aggregation, involved in Alzheimer's disease (AD).

Novel magnetic fibrin hydrogel scaffolds containing thrombin and growth factors conjugated iron oxide nanoparticles for tissue engineering.

Novel tissue-engineered magnetic fibrin hydrogel scaffolds were prepared by the interaction of thrombin-conjugated iron oxide magnetic nanoparticles with fibrinogen. In addition, stabilization of basal fibroblast growth factor (bFGF) was achieved by the covalent and physical conjugation of the growth factor to the magnetic nanoparticles. Adult nasal olfactory mucosa (NOM) cells were seeded in the transparent fibrin scaffolds in the absence or presence of the free or conjugated bFGF-iron oxide nanoparticles.

Enhancement of the growth and differentiation of nasal olfactory mucosa cells by the conjugation of growth factors to functional nanoparticles.

Growth factors are critical components in the tissue engineering approach. Basic fibroblast growth factor (bFGF), a representative growth factor, stimulates the cellular functions of various cells and has been used extensively for the repair and regeneration of tissues. The in vivo half-life time of free bFGF is short, about 3-10 min, due to rapid enzymatic degradation.

Synthesis of fluorescent-maghemite nanoparticles as multimodal imaging agents for amyloid-beta fibrils detection and removal by a magnetic field.

Early diagnosis in Alzheimer's disease (AD), before the onset of marked clinical symptoms, is critical in preventing the irreversible neuronal damage that eventually leads to dementia and ultimately death. Therefore, there is an urgent need for in vivo imaging agents, which are valuable as specific biomarkers to demonstrate the location and density of amyloid plaques in the living human brain. The present manuscript describes a novel method for selective marking of Abeta(40) fibrils by non-fluorescent gamma-Fe(2)O(3) and fluorescent-magnetic gamma-Fe(2)O(3)-rhodamine or gamma-Fe(2)O(3)-Congo red nanoparticles, and the complete removal of the magnetized fibrils from the aqueous continuous phase by a magnetic field.

Synthesis and characterization of fluorinated magnetic core-shell nanoparticles for inhibition of insulin amyloid fibril formation.

Maghemite (gamma-Fe2O3) magnetic nanoparticles of 15.0 +/- 2.1 nm are formed by nucleation followed by controlled growth of maghemite thin films on gelatin-iron oxide nuclei.

Effect of maghemite nanoparticles on insulin amyloid fibril formation: selective labeling, kinetics, and fibril removal by a magnetic field.

Maghemite (gamma-Fe(2)O(3)) magnetic nanoparticles of 15.0 +/- 2.1 nm were formed by nucleation followed by controlled growth of maghemite thin films on gelatin-iron oxide nuclei.