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Carboxymethylcellulose (CMC) and keratin nanoparticle (KNP) hydrogels were obtained, characterized, and applied as drug delivery systems (DDSs) for the first time. Lyophilized CMC/KNP mixtures containing 10, 25, and 50 wt% of KNPs were kept at 170 °C for 90 min to crosslink CMC chains through a solid-state reaction with the KNPs. The hydrogels were characterized by infrared spectroscopy, thermal analyses, X-ray diffraction, mechanical measurements, and scanning electron microscopy. The infrared spectra indicated the formation of ester and amide linkages between crosslinked CMC and KNPs. The elastic modulus of the hydrogel containing 10 wt% KNPs was 2-fold higher than that of the hydrogel containing 50 wt% KNPs. The mechanical properties influenced the hydrogel stability and water uptake. The anti-inflammatory prednisolone (PRED) drug was incorporated into the hydrogels, and the release mechanism was investigated. The hydrogels supported PRED release by drug desorption for approximately 360 h. A sustained release mechanism was achieved. The CMC/KNP and CMC/KNP/PRED hydrogels were cytocompatible toward mammalian cells. The CMC/KNP/PRED set imparted the highest cell viability after 7 days of incubation. This study showed a straightforward procedure to create DDSs (chemically crosslinked) based on polysaccharides and proteins for efficient PRED delivery., Competing Interests: Declaration of competing interest The authors have no competing financial interests to declare or personal relationships that can influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The direct delivery of growth factors to sites of tissue healing is complicated by their relative instability. In many tissues, the glycosaminoglycan (GAG) side chains of proteoglycans like aggrecan stabilize growth factors in the pericellular and extracellular space, creating a local reservoir that can be accessed during a wound healing response. GAGs also regulate growth factor-receptor interactions at the cell surface. Here we report the development of nanoparticles for growth factor delivery that mimic the size, GAG composition, and growth factor binding and stabilization of aggrecan. The aggrecan-mimetic nanoparticles are easy to assemble, and their structure and composition can be readily tuned to alter their physical and biological properties. We use basic fibroblast growth factor (FGF-2) as a model heparin-binding growth factor, demonstrating that aggrecan-mimetic nanoparticles can preserve its activity for more than three weeks. We evaluate FGF-2 activity by measuring both the proliferation and metabolic activity of bone marrow stromal cells to demonstrate that chondroitin sulfate-based aggrecan mimics are as effective as aggrecan, and heparin-based aggrecan mimics are superior to aggrecan as delivery vehicles for FGF-2.

Here we present a novel matrix-mimetic nanoassembly based on polysaccharides. Chitosan electrospun fiber networks are decorated with heparin-containing polyelectrolyte complex nanoparticles (PCNs) that present basic fibroblast growth factor (FGF-2), both stably adsorbed to the surfaces and released into solution. These FGF-2/PCN complexes can be released from the fibers with zero-order kinetics over a period of 30 days. Further modification of fibers with a single bilayer of polyelectrolyte multilayer (PEM) composed of N,N,N-trimethyl chitosan and heparin completely prevent release, and the FGF-2/PCN complexes are retained on the fibers for the duration of the release experiment (30 days). We also compare the mitogenic activity of these FGF-2/PCN complexes delivered in two different states: adsorbed to a surface and dissolved in solution. FGF-2/PCN complexes exhibit mitogenic activity with respect to ovine bone marrow-derived mesenchymal stem cells, even after being preconditioned by incubating for 27 days at 37°C in solution. However, when the FGF-2/PCN complexes are adsorbed to chitosan and coated with PEMs, the mitogenic activity of the FGF-2 steadily decreases with increasing preconditioning time. This work demonstrates a new system for stabilizing and controlling the delivery of heparin-binding growth factors, using polysaccharide-based matrix-mimetic nanomaterials. This work also contributes to our understanding of the preferred mode of growth factor delivery from porous scaffolds., (Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

The influence of particle size on the activity and recycling capabilities of enzyme conjugated magnetic nanoparticles was studied. Co-precipitation and oxidation of Fe(OH)(2) methods were used to fabricate three different sizes of magnetic nanoparticles (5 nm, 26 nm and 51 nm). Glucose oxidase was covalently bound to the magnetic nanoparticles by modifying the surfaces with 3-(aminopropyl)triethoxysilane (APTES) and a common protein crosslinking agent, glutaraldehyde. Analysis by Transmission Electron Microscopy (TEM) showed that the morphology of the magnetic nanoparticles to be spherical and sizes agreed with results of the Brunauer, Emmett, and Teller (BET) method. Magnetic strength of the nanoparticles was analyzed by magnetometry and found to be 49 emu g(-1) (5 nm), 73 emu g(-1) (26 nm), and 85 emu g(-1) (51 nm). X-ray photoelectron spectroscopy (XPS) confirmed each step of the magnetic nanoparticle surface modification and successful glucose oxidase binding. The immobilized enzymes retained 15-23% of the native GOx activity. Recycling stability studies showed approximately 20% of activity loss for the large (51 nm) and medium (26 nm) size glucose oxidase-magnetic nanoparticle (GOx-MNP) bioconjugate and about 96% activity loss for the smallest GOx-MNP bioconjugate (5 nm) after ten cycles. The bioconjugates demonstrated equivalent total product conversions as a single reaction of an equivalent amount of the native enzyme after the 5th cycle for the 26 nm nanoparticles and the 7th cycle for the 51 nm nanoparticles., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Nanoscale chemical and topographical features have been demonstrated to influence a variety of significant responses of mammalian cells to biomaterials surfaces. Thus, an important goal for biomaterials scientists is the ability to engineer the nanoscale surface features of biologically active materials. The goal of the current work is to demonstrate that polyelectrolyte complex nanoparticles (PCNs) in polyelectrolyte multilayers (PEMs) can be combined to create surfaces with controlled nanoscale surface topography and nanoscale presentation of surface chemistry. The polysaccharides used in this work are the biomedically relevant chitosan, heparin, and hyaluronan. Nanostructured surface coatings were characterized on both modified gold substrates and tissue-culture polystyrene surfaces. PCNs were adsorbed to oppositely charged PEMs, and were also embedded within PEMs. The construction of the surface coatings was characterized by quartz crystal microbalance with dissipation (QCM-D). The surface morphology was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The chemistry of the coatings was confirmed by both X-ray photoelectron spectroscopy (XPS) and polarization modulation infra-red reflection absorption spectroscopy (PM-IRRAS). Morphologically, we found that PCNs were colloidally stable and homogeneously distributed when adsorbed on or in the PEMs. Chemical analysis confirms that the PCNs adsorbed to PEMs significantly altered the surface chemistry, indicating significant surface coverage. Furthermore, the position of the PCNs normal to the surface can be adjusted by adding PEMs on top of adsorbed PCNs. Thus, PCNs can be used to introduce discrete nanoscale surface topographical features and varying surface chemistry into PEM surface coatings in a controlled way., (2010 Elsevier B.V. All rights reserved.)

The formation of polyelectrolyte complex nanoparticles (PCN) was investigated at different charge mixing ratios for the chitosan-heparin (chi-hep) and chitosan-hyaluronan (chi-ha) polycation-polyanion pairs. The range of 0.08-19.2 for charge mixing ratio (n(+)/n(-)) was examined. The one-shot addition of polycation and polyanion solutions used for the formation of the PCN permitted formation of both cationic and anionic particles from both polysaccharide pairs. The influence of the charge mixing ratio on the size and zeta potential of the particles was investigated. The morphology and stability of the particles when adsorbed to surfaces was studied by scanning electron microscopy (SEM). For most conditions studied, colloidally stable, nonstoichiometric PCN were formed in solution. However, PCN formation was inhibited by flocculation at charge mixing ratios near 1. When adsorbed to surfaces and dried, some formulations resulted in discrete nanoparticles, while others partially or completely aggregated or coalesced, leading to different surface morphologies.

Blood vessels present a dense, non-uniform, polysaccharide-rich layer, called the endothelial glycocalyx. The polysaccharides in the glycocalyx include polyanionic glycosaminoglycans (GAGs). This polysaccharide-rich surface has excellent and unique blood compatibility. We report new methods for preparing and characterizing dense GAG surfaces that can serve as models of the vascular endothelial glycocalyx. The GAG-rich surfaces are prepared by adsorbing heparin or chondroitin sulfate-containing polyelectrolyte complex nanoparticles (PCNs) to chitosan-hyaluronan polyelectrolyte multilayers (PEMs). The surfaces are characterized by PeakForce tapping atomic force microscopy, both in air and in aqueous pH 7.4 buffer, and by PeakForce quantitative nanomechanics (PF-QNM) mode with high spatial resolution. These new surfaces provide access to heparin-rich or chondroitin sulfate-rich coatings that mimic both composition and nanoscale structural features of the vascular endothelial glycocalyx. [ABSTRACT FROM AUTHOR]

In this work, titania (TiO2) nanoparticles modified by Eu(TTA)3Phen complexes (ETP) were prepared by a simple solvothermal method developing a fluorescence Mn7+ pollutant sensing system. The characterization results indicate that the ETP cause structural deformation and redshifts of the UV-visible light absorptions of host TiO2 nanoparticles. The ETP also reduce the crystallinity and crystallite size of TiO2 nanoparticles. Compared with TiO2 nanoparticles modified with Eu3+ (TiO2-Eu3+), TiO2 nanoparticles modified with ETP (TiO2-ETP) exhibit significantly stronger photoluminescence under the excitation of 394 nm. Under UV excitation, TiO2-ETP nanoparticles showed blue and red emission corresponding to TiO2 and Eu3+. In addition, as the concentration of ETP in TiO2 nanoparticles increases, the PL intensity at 612 nm also increases. When ETP-modified TiO2 nanoparticles are added to an aqueous solution containing Mn7+, the fluorescence intensity of both TiO2 and ETP decreases. The evolution of the fluorescence intensity ratio (I1/I2) of TiO2 and ETP is linearly related to the concentration of Mn7+. The sensitivity of fluorescence intensity to Mn7+ concentration enables the design of dual fluorescence ratio solid particle sensors. The method proposed here is simple, accurate, efficient, and not affected by the environmental conditions. [ABSTRACT FROM AUTHOR]

A novel anhydrous preparation of silica (SiO2)-encapsulated terbium (Tb3+) complex nanoparticles has been investigated. The SiO2-Tb3+ nanoparticles are incorporated in electrospun polyvinylpyrrolidone hybrid nanofibers. Transmission electron microscopy confirms that Tb3+ complexes are uniformly and stably encapsulated in or carried by nanosilica. The influence of pH on the fluorescence of Tb3+ complexes is discussed. The properties, composition, structure, and luminescence of the resulting SiO2–Tb3+ hybrid nanoparticles are investigated in detail. There is an increase in the fluorescence lifetime of SiO2–Tb3+ nanoparticles and SiO2–Tb3+/polyvinylpyrrolidone (PVP) hybrid nanofibers compared with the pure Tb3+ complexes. Due to the enhanced optical properties, the fluorescent hybrid nanofibers have potential applications as photonic and photoluminescent materials. [ABSTRACT FROM AUTHOR]

Novel Stöber derived silica nanoparticles doped with europium complexes [Eu(tta) 3 phen]by two-step alkaline hydrolysis method have been fabricated in order to design stable luminescent hybrid nanoparticles with fine particle size. Isotactic polypropylene (iPP) was doped with long-lifetime (τ = 859.2 µs) luminescent nanoparticles via twin screw extrusion. The composition, structure and luminescence properties of the resulting hybrid nanoparticles were investigated in detail. STEM revealed that europium complexes were encapsulated homogenously and stably in nano silica. The luminescence measurements combined with bright red color photographs confirm the red light emission due to trivalent europium ions, while the intensity increases with the increase of corresponding doped concentrations of SiO 2 -Eu 3+ nanoparticles in iPP hybrid materials. The melt processable luminescent optical fibers reported here is a novel application of rare earth complexes that can be used to develop new photonic and electronic materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acid hydrolysis was used to extract keratin nanoparticles from human hair. • The KNPs effectively released berberine for ∼6 h. • Nanoparticles presented cytoocompatibility against mesenchymal adipose stem cells. • The keratin nanoparticles exhibited strong photothermal properties. • Human hair keratin nanoparticles were developed for cancer treatment purposes. Human hair can be a sustainable keratin source to prepare cytocompatible drug nanocarriers. A simple and effective methodology to create rod-like keratin nanoparticles (KNPs) using acidic hydrolysis was reported in this work. The extracted KNPs were characterized by infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermal analysis (TG and DSC), Zeta potential measurements, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The KNPs presented an amorphous structure with a smaller average size and higher aspect ratio than KNPs created from previously reported alkaline methods. Furthermore, cell viability assays confirmed that the extracted KNPs are cytocompatible toward adipose mesenchymal stem cells (ADSCs) and healthy cells of the African green monkey (VERO cells). The material was evaluated as berberine (BERB) nanocarrier, a drug with anticancer activity. The BERB was associated with KNPs by adsorption. The rod-shaped KNPs presented a type II adsorption profile toward BERB, adsorbing approximately 168.05 ± 1.44 mg/g. BERB is a cationic species capable of interacting with negatively charged KNPs (Zeta potential equal to −33.8 mV at pH 8.0). After BERB adsorption, the KNPs/BERB Zeta potential is reduced to −10.14 mV (pH 8.0). The KNPs exhibited strong photothermal properties, which improved and enhanced the BERB desorption. The photothermal KNPs responsiveness promoted a sustained BERB release. The KNPs/BERB shows cytotoxity against colon adenocarcinoma cells (HT-29 cells). Therefore, the extracted rod-shaped KNPs can be alternative nanocarriers for BERB delivery. [ABSTRACT FROM AUTHOR]

Novel non-toxic Eu3+-induced polyelectrolyte nano-aggregates (EIPAs) are used as a light-emitting nanomaterial to sense bacteria on the surface of cotton fabric. EIPAs are formed through coordination interaction between Eu3+(tta) 3 phen complexes with positive charges and polyanionic hyaluronic acid (HA) with negative charges, and EIPAs were chemically bonded onto cotton fabrics through pentaerythritol (PER) crosslinking. Based on this innovation, the obtained fluorescence cotton fabrics (FCF) have a wide excitation spectrum, intense emission spectrum, and long fluorescence lifetime, which makes the fabric fluorescence stable and bright. These EIPAs and their photophysical properties impart FCF with the ability to report both Staphylococcus aureus and Escherichia coli. Furthermore, FCF has antibacterial activity against Staphylococcus aureus. Therefore, this new FCF integrates the advantages of superior lanthanide fluorescence, non-cytotoxicity, antibacterial activity, wearable and smart sensing. • The feasibility of bacterial contamination sensing just with the fluorescence of EIPAs on FCF. • EIPAs with high quantum yield, long lifetime and biocompatible polyelectrolytes were chemically bonded onto cotton fabrics. • As the key advantages, fluorescent cotton fabrics is a non-toxic, biocompatible, wearable and smart sensing fabric. [ABSTRACT FROM AUTHOR]