Bovine Serum Albumin Scaffold Research Articles

Improving the colonization and functions of Wharton’s Jelly-derived mesenchymal stem cells by a synergetic combination of porous polyurethane scaffold with an albumin-derived hydrogel

The development of neo-tissues assisted by artificial scaffolds is continually progressing, but the reproduction of the extracellular environment surrounding cells is quite complex. While synthetic scaffolds can support cell growth, they lack biochemical cues that can prompt cell proliferation or differentiation. In this study, Wharton’s Jelly-derived mesenchymal stem cells are seeded on a polyurethane (PU) scaffold combined with a hydrogel based on bovine serum albumin (BSA). BSA hydrogel is obtained through thermal treatment. While such treatment leads to partial unfolding of the protein, we show that the extent of denaturation is small enough to maintain its bioactivity, such as protein binding. Therefore, BSA provides a suitable playground for cells inside the scaffold, allowing higher spreading, proliferation and matrix secretions. Furthermore, the poor mechanical properties of the hydrogel are compensated for by the porous PU scaffold, whose architecture is well controlled. We show that even though PU by itself can allow cell adhesion and protein secretion, cell proliferation is 3.5 times higher in the PU + BSA scaffolds as compared to pure PU after 21 d, along with the non-collagenous protein secretions (389 versus 134 μmmg−1). Conversely, the secretion of sulphated glycosaminoglycans is 12.3-fold higher in the scaffold made solely of PU. Thereby, we propose a simple approach to generating a hybrid material composed of a combination of PU and BSA hydrogel as a promising scaffold for tissue regeneration.

Improved enzymatic assay for hydrogen peroxide and glucose by exploiting the enzyme-mimicking properties of BSA-coated platinum nanoparticles.

Platinum nanoparticles (Pt NPs) covered with a bovine serum albumin scaffold and a particle size of 1.5nm (BSA-PtS NPs) are shown to display enhanced multiple enzyme-mimicking activities including peroxidase, oxidase, and catalase-like activities. The peroxidase-like activity is characterized by robustness and low signal background. BSA-PtS NPs were used to design colorimetric assays for H2O2 and glucose. H2O2 latter reacts with 3,3',5,5'-tetramethylbenzidine in the presence of BSA-PtS NPs to form a blue product with an absorption maximum at 652nm. The assay works in the 5-250μM H2O2 concentration range. The glucose assay is based on its glucose oxidase-catalyzed oxidation to produce gluconic acid and H2O2 which then is colorimetrically quantified. Response is linear in the 10-120μM glucose concentration range, and the detection limit is 2μM (at S/N = 3). The method correlates well with the glucose standard method (R2 = 0.997 in the 95% confidence interval) which confirms that glucose in human serum has been successfully detected. Graphical abstractImproved enzymatic assay for hydrogen peroxide and glucose by exploiting the enzyme-mimicking properties of BSA-coated platinum nanoparticles.

Fabrication, mechanical property and in vitro evaluation of poly (L-lactic acid-co-ε-caprolactone) core-shell nanofiber scaffold for tissue engineering

Coaxial electrospinning, in which Poly (L-lactic acid-co-ε-caprolactone) (PLC) with different Lactic acid (LA) to caprolactone (CL) ratio (75:25 and 50:50) were employed to electrospin core-shell nanofibers which could mimic the native extracellular matrix for tissue engineering applications. Core-shell nanofibrous scaffolds of PLC (50:50)/BSA (426 ± 157 nm) and PLC (75:25)/BSA (427 ± 197 nm) were fabricated and model drug bovine serum albumin (BSA) was entrapped in the core layer. The morphology, core-shell structure and sustained release behaviors were evaluated by Scanning electron microscopy (SEM), transmission electron microscopy (TEM), inverted fluorescence microscopy, water contact angle test and in vitro release test, respectively. The effect of core-shell structure and shell layer materials on the variation tendency of mechanical characterization in dry and wet situation were also investigated by tensile testing. The in vitro biocompatibility of scaffolds were investigated by growing human mesenchymal stem cells (hMSCs) on scaffolds surface and the proliferation of cells were evaluated with Alamar Blue tests. In vitro cultivations of hMSCs showed that PLC (50:50)/BSA scaffolds supported a significantly higher proliferation rate of seeded cells than scaffolds prepared by polymer PLC (75:25)/BSA. Overall, the PLC core-shell nanofibers possessed potentially regulable mechanical properties useful for tissue engineering as well as sustained release potential for medical applications.

Green Fluorescent Protein Nanovessel Serves as a Nucleolus Targeting Material and Molecule Carrier in Living Cells.

The nucleolus is responsible for RNA transcription, processing, and ribosome assembly, the dysfunction of which is associated with a number of diseases. In this report, a new member of fluorescent protein nanovessels (FPNs), constructed using thioflavin-T (ThT) and bovine serum albumin (BSA) as building blocks, is described. As a popular amyloid specific dye, ThT is nonfluorescent by itself, while its fluorescence can be lighted up upon interacting with amyloid proteins. Herein, ThT is coassembled with the BSA scaffold at high temperature to form T(hT)-FPNs. These green fluorescence emissive bio-abiotic hybrid materials can serve as a novel probe for real-time nucleolus imaging of living cells. Besides, T-FPNs show potential in delivering insoluble and/or impenetrable drugs into living cells, suggesting another role as a molecule carrier.

Protein-Stabilized Gadolinium Oxide-Gold Nanoclusters Hybrid for Multimodal Imaging and Drug Delivery.

A protein-stabilized multifunctional theranostic nanoplatform, gadolinium oxide-gold nanoclusters hybrid (Gd2O3-AuNCs), is constructed for multimodal imaging and drug delivery. The Gd2O3-AuNCs nanohybrid is developed by integrating Gd2O3 nanocrystals and gold nanoclusters into bovine serum albumin scaffold as a stabilizer. The nanohybrid exhibits favorable biocompatibility and is capable of enhancing the contrast in magnetic resonance and X-ray computed tomography imaging. Meanwhile, the integrated AuNCs component not only endows the nanohybrid to produce red fluorescence, but also sensitizes the generation of singlet oxygen (1O2) upon near-infrared laser stimulation at 808 nm. Bovine serum albumin surrounding the nanoparticles makes Gd2O3-AuNCs a brilliant carrier for the delivery of indocyanine green (ICG). ICG loading endows the Gd2O3-AuNCs-ICG nanocomposite with a near-infrared fluorescence imaging capability, and improves its photodynamic property and photothermal capability. Ultimately, further experiments have demonstrated that Gd2O3-AuNCs-ICG nanocomposite is a promising theranostic agent for image guided cancer therapy.

Fabrication of Nerve Growth Factor Encapsulated Aligned Poly(ε-Caprolactone) Nanofibers and Their Assessment as a Potential Neural Tissue Engineering Scaffold.

Peripheral nerve injury is a serious clinical problem to be solved. There has been no breakthrough so far and neural tissue engineering offers a promising approach to promote the regeneration of peripheral neural injuries. In this study, emulsion electrospinning technique was introduced as a flexible and promising technique for the fabrication of random (R) and aligned (A) Poly(ε-caprolactone) (PCL)-Nerve Growth Factor (NGF)&Bovine Serum Albumin (BSA) nanofibrous scaffolds [(R/A)-PCL-NGF&BSA], where NGF and BSA were encapsulated in the core while PCL form the shell. Random and aligned pure PCL, PCL-BSA, and PCL-NGF nanofibers were also produced for comparison. The scaffolds were characterized by Field Emission Scanning Electron Microscopy (FESEM) and water contact angle test. Release study showed that, with the addition of stabilizer BSA, a sustained release of NGF from emulsion electrospun PCL nanofibers was observed over 28 days. [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt; MTS] assay revealed that (R/A)-PCL-NGF and (R/A)-PCL-NGF&BSA scaffolds favored cell growth and showed no cytotoxicity to PC12 cells. Laser scanning confocal microscope images exhibited that the A-PCL-NGF&BSA scaffold increased the length of neurites and directed neurites extension along the fiber axis, indicating that the A-PCL-NGF&BSA scaffold has a potential for guiding nerve tissue growth and promoting nerve regeneration.

Aggregation-induced structure transition of protein-stabilized zinc/copper nanoclusters for amplified chemiluminescence.

A stable, water-soluble fluorescent Zn/Cu nanocluster (NC) capped with a model protein, bovine serum albumin (BSA), was synthesized and applied to the reaction of hydrogen peroxide and sodium hydrogen carbonate. A significantly amplified chemiluminescence (CL) from the accelerated decomposition of peroxymonocarbonate (HCO4(-)) by the nanosluster was observed. The CL reaction led to a structure change of BSA and aggregation of Zn/Cu NCs. In the presence of H2O2, Zn/Cu-S bonding between BSA scaffolds and the encapsulated Zn/Cu@BSA NC was oxidized to form a disulfide product. Zn/Cu@BSA NCs were prone to aggregate to form larger nanoparticles without the protection of scaffolds. It is revealed that the strong CL emission was initiated from the catalysis of Zn/Cu@BSA NC and the surface plasmon coupling of the formed Zn/Cu nanoparticles in a single chemical reaction. This amplified CL was successfully exploited for selective sensing of hydrogen peroxide in environmental samples.

Fabrication of three-dimensional multi-protein microstructures for cell migration and adhesion enhancement.

In this study, three-dimensional (3D) multi-component microstructures were precisely fabricated via multiphoton excited photochemistry using a femtosecond laser direct-writing system with proposed repetition positioning and vector scanning techniques. Extracellular matrix (ECM) proteins, such as fibronectin (FN), are difficult to stack and form 3D structures larger than several-hundred microns in height due to the nature of their protein structure. Herein, to fabricate complex 3D microstructures with FN, a 3D scaffold was designed and formed from bovine serum albumin (BSA), after which human FN was inserted at specific locations on the BSA scaffold; in this manner, the fabricated ECM microstructure can guide cells in a 3D environment. A human breast cancer cell line, MDA-MB-231, was used to investigate the behavior of cell migration and adhesion on the fabricated human FN and BSA protein structures. Experimental results indicate that many cells are not able to attach or climb on a 3D structure's inclined plane without FN support; hence, the influence of cell growth in a 3D context with FN should being taken into consideration. This 3D multi-protein fabrication technique holds potential for cell studies in designed complex 3D ECM scaffolds.

Novel preparation of controlled porosity particle/fibre loaded scaffolds using a hybrid micro-fluidic and electrohydrodynamic technique

The purpose of this research was to produce multi-dimensional scaffolds containing biocompatible particles and fibres. To achieve this, two techniques were combined and used: T-Junction microfluidics and electrohydrodynamic (EHD) processing. The former was used to form layers of monodispersed bovine serum albumin (BSA) bubbles, which upon drying formed porous scaffolds. By altering the T-Junction processing parameters, bubbles with different diameters were produced and hence the scaffold porosity could be controlled. EHD processing was used to spray or spin poly(lactic-co-glycolic) (PLGA), polymethysilsesquioxane (PMSQ) and collagen particles/fibres onto the scaffolds during their production and after drying. As a result, multifunctional BSA scaffolds with controlled porosity containing PLGA, PMSQ and collagen particles/fibres were obtained. Product morphology was studied by optical and scanning electron microscopy. These products have potential applications in many advanced biomedical, pharmaceutical and cosmetic fields e.g. bone regeneration, drug delivery, cosmetic cream lathers, facial scrubbing creams etc.

Polycaprolactone and Bovine Serum Albumin Based Nanofibers for Controlled Release of Nerve Growth Factor

Tissue engineering approaches for peripheral nerve regeneration employ biodegradable scaffolds coupled with growth factors for improved performance in regeneration of large nerve injuries. Electrospun nanofibers provide a versatile platform for fabrication of scaffolds with extracellular matrix like architecture and increased surface area. Incorporation of growth factors in nanofibers have been previously demonstrated using oil in water emulsion techniques but are associated with burst release and loss of valuable growth factor. Here, we show a novel blend of polycaprolactone and bovine serum albumin (BSA) to form nanofibers containing nerve growth factors. The BSA helps in overcoming the most common drawbacks associated with hydrophobic polymers such as reduced loading efficiency, long degradation periods, and burst release. The controlled release of nerve growth factor (NGF) from the nanofibers was evaluated using enzyme linked immune sorbent assay (ELISA) and PC12 based bioassay over a 28 day time period. A sustained release of NGF was obtained for at least 28 days. PC12 bioassays confirmed the bioactivity of the NGF, and showed that the released NGF was sufficient to induce neurite outgrowth from PC12 cells throughout the period of release, therefore, demonstrating the successful incorporation and controlled release potential of PCL BSA scaffolds.

Solder doped polycaprolactone scaffold enables reproducible laser tissue soldering

In this in vitro feasibility study we analyzed tissue fusion using bovine serum albumin (BSA) and Indocyanine green (ICG) doped polycaprolactone (PCL) scaffolds in combination with a diode laser as energy source while focusing on the influence of irradiation power and albumin concentration on the resulting tensile strength and induced tissue damage. A porous PCL scaffold doped with either 25% or 40% (w/w) of BSA in combination with 0.1% (w/w) ICG was used to fuse rabbit aortas. Soldering energy was delivered through the vessel from the endoluminal side using a continuous wave diode laser at 808 nm via a 400 microm core fiber. Scaffold surface temperatures were analyzed with an infrared camera. Optimum parameters such as irradiation time, radiation power and temperature were determined in view of maximum tensile strength but simultaneously minimum thermally induced tissue damage. Differential scanning calorimetry (DSC) was performed to measure the influence of PCL on the denaturation temperature of BSA. Optimum parameter settings were found to be 60 seconds irradiation time and 1.5 W irradiation power resulting in tensile strengths of around 2,000 mN. Corresponding scaffold surface temperature was 117.4+/- 12 degrees C. Comparison of the two BSA concentration revealed that 40% BSA scaffold resulted in significant higher tensile strength compared to the 25%. At optimum parameter settings, thermal damage was restricted to the adventitia and its interface with the outermost layer of the tunica media. The DSC showed two endothermic peaks in BSA containing samples, both strongly depending on the water content and the presence of PCL and/or ICG. Diode laser soldering of vascular tissue using BSA-ICG-PCL-scaffolds leads to strong and reproducible tissue bonds, with vessel damage limited to the adventitia. Higher BSA content results in higher tensile strengths. The DSC-measurements showed that BSA denaturation temperature is lowered by addition of water and/or ICG-PCL.