Journal of biomedical materials research. Part A最新文献

Triggered by the vulnerability to atherosclerotic plaques, cardiovascular diseases (CVDs) have become a main reason for high mortality worldwide. Thus, there is an urgent need to develop functional molecular imaging modalities to improve the detection rate of vulnerable plaques. In this study, polyethyleneimine (PEI) was coated on the surface of mesoporous silica nanoprobes (MSN) loaded with Gd₂O₃ (MSN@Gd₂O₃), followed by coupling the fluorescent dye carboxylated heptamethine cyanine (IR808), and then the dextran sulfate (DS) was modified on the surface of MSN@Gd₂O₃@IR808 by electrostatic adsorption, to construct a targeted and pH-responsive magnetic resonance (MR)/near-infrared fluorescence imaging (NIRF) dual-modal nanoprobe (MSN@Gd₂O₃@IR808@DS nanoparticles). The nanoprobe presented a more concentrated distribution of spherical shapes in transmission electron microscopy. In vitro simulated vulnerable plaque microenvironment (pH = 5.5) presented significant T₁-weighted imaging (T₁WI) signal and longitudinal relaxation in the nanoprobe. Immunofluorescence staining and cellular uptake assays showed that MSN@Gd₂O₃@IR808@DS nanoparticles have the ability to specially bind to scavenger receptors A (SR-A). In vascular endothelium from the high-fat diet (HFD) New Zealand White rabbits, MSN@Gd₂O₃@IR808@DS nanoparticles can exhibit specific contrast-enhanced signals by MR/NIRF dual-modal imaging. In addition, cytotoxicity assays and hematoxylin and eosin (H&E) staining results demonstrated that MSN@Gd₂O₃@IR808@DS nanoparticles have good biocompatibility. Hence, this multifunctional MR/NIRF bimodal nanoprobe provides new experimental and technological ideas for the accurate diagnosis of vulnerable plaques.

Tendinopathy is a disorder characterized by pain and reduced function due to a series of changes in injured or diseased tendons. Inflammation and collagen degeneration are key contributors to the onset and chronic nature of tendinopathy. Acetyl-11-keto-β-boswellic acid (AKBA) is an effective anti-inflammatory agent widely used in chronic inflammatory disorders and holds potential for tendinopathy treatment; however, its therapeutic efficacy is limited by poor aqueous solubility. Here, we fabricated AKBA-encapsulated cationic liposome-gelatin methacrylamide (GelMA) microspheres (GM-Lipo-AKBA) using thin-film hydration and microfluidic technology for drug delivery therapy. GM-Lipo-AKBA exhibited high encapsulation efficiency, extended AKBA release for over 4 weeks, and prolonged degradation. In vitro and in vivo experiments demonstrated its effectiveness in improving inflammation and ECM remodeling in tendinopathy. In summary, the injectable nano-micron drug delivery platform provides a promising strategy for the sustained and localized delivery of AKBA for tendinopathy treatment.

Gamma irradiation is an effective technique for biocomposite films intended for application in tissue engineering (TE) to ensure sterility and patient safety prior to clinical applications. This study proposed a biocomposite film composed of natural polymer chitosan (CS) and synthetic polymer poly-Ɛ-caprolactone (PCL) reinforced with sol–gel-derived bioactive glass (BG) for potential application in TE. The BG/PCL/CS biocomposite film was sterilized using 25 kGy gamma rays, and subsequent changes in its characteristics were analyzed through mechanical and physical assessment, bioactivity evaluation via immersion in simulated body fluid (SBF) and biocompatibility examination using human primary dermal fibroblasts (HPDFs). Results indicated a homogeneous distribution of BG particles within the BG/PCL/CS polymer matrix which enhanced bioactivity, and the polymer blend provide a structurally stable film. Gamma irradiation induced an increase in the film's surface roughness due to photo-oxidative degradation; however, this did not adversely affect the integrity of glass particles and polymer chains. In vitro assessments demonstrated hydroxyapatite formation on the film's surface, suggesting bioactivity. Biocompatibility testing confirmed enhanced cell adhesion and proliferation. These multifunctional properties highlight the potential of the fabricated BG/PCL/CS biocomposite film for TE and regenerative medicine applications.

The high bioactivity and biocompatibility of hydroxyapatite (HAP) make it a useful bone graft material for bone tissue engineering. However, the development superior osteoconductive and osteoinductive materials for bone regeneration remains a challenge. To overcome these constraints, Cu-doped hydroxyapatite (HAP(Cu)) from waste eggshells has been produced for bone tissue engineering. The materials produced were characterized using Fourier transform infrared spectroscopy, x-ray diffraction, and photoelectron spectroscopy. The scanning microscopy images revealed that the developed HAP was a rod-like crystalline structure with a typical 80–150 nm diameter. Energy-dispersive x-ray spectroscopy showed that the generated HAP was mostly composed of calcium, oxygen, and phosphorus. The Ca/P molar ratios in eggshell-derived and copper-doped HAP were 1.61 and 1.67, respectively, similar to the commercially available HAP ratio (1.67). The WST-8 assay was used to assess the biocompatibility of HAPs with hBMSCs. HAP(Cu) in the media significantly altered the cytotoxicity of biocompatible HAP(Cu). The osteogenic potential of HAP(Cu) was demonstrated by greater mineralization than that of pure HAP or the control. HAP(Cu) showed higher osteogenic gene expression than pure HAP and the control, indicating its stronger osteogenic potential. Furthermore, we assessed the effects of sample-treated macrophage-derived conditioned medium (CM) on hBMSCs' osteogenesis. CM-treated HAP(Cu) demonstrated a significantly higher osteogenic potential vis-à-vis pure HAP(Cu). These findings revealed that HAP(Cu) with CM significantly improved osteogenesis in hBMSCs and can be explored as a bone graft in bone tissue engineering.

Nanoparticle-laden contact lenses are a formidable strategy for ocular drug delivery. However, incorporating nanoparticles to achieve sustained drug release without affecting the contact lenses' properties remains a challenging task. In this work, daily and monthly replacement silicone-hydrogel contact lenses laden with bovine serum albumin/hyaluronic acid (BSA/HA) nanoparticles are presented. These nanoparticle-laden contact lenses enable the sustained release of 5-fluorouracil (5-FU) in mimetic physiological conditions. The nanoparticle-laden contact lenses display properties similar to neat contact lenses, including refractive index, water content, UV/visible transmittance and chemical structure. Noteworthy attributes include the BSA/HA nanoparticles' low polydispersity, negative surface charge and a hydrodynamic size of ~210 nm, as well as the high nanoparticle loading efficiency (~ 30%) of the contact lenses. Thereby, the BSA/HA nanoparticles are a promising strategy for developing nanoparticle-laden contact lenses for therapeutic applications, namely for sustained drug delivery.

Conductive hydrogels have gained interest in biomedical applications and soft electronics. To tackle the challenge of ionic hydrogels falling short of desired mechanical properties in previous studies, our investigation aimed to understand the pivotal structural factors that impact the conductivity and mechanical behavior of polyethylene glycol (PEG)-based hydrogels with ionic conductivity. Polyether urethane diacrylamide (PEUDAm), a functionalized long-chain macromer based on PEG, was used to synthesize hydrogels with ionic conductivity conferred by incorporating ions into the liquid phase of the hydrogel. The impact of salt concentration, water content, temperature, and gel formation on both mechanical properties and conductivity was characterized to establish parameters for tuning hydrogel properties. To further expand the range of conductivity available in these ionic hydrogels, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was incorporated as a single copolymer network or double network configuration. As expected, conductivity in these ionic gels was primarily driven by ion diffusivity and charge density, which were dependent on hydrogel network formation and swelling. Copolymer network structure had minimal effect on the conductivity, which was primarily driven by counter-ion equilibrium; however, the mechanical properties and equilibrium swelling were strongly dependent on network structure. The structure–property relationships elucidated here enable the rationale design of this new double network hydrogel to achieve target properties for a broad range of biomedical applications.