RhBMP-2-loaded Poly(lactic-co-glycolic acid) microspheres fabricated by coaxial electrospraying for protein delivery

Impregnation of polyethylene terephthalate (PET) grafts with BMP-2 loaded functional nanoparticles for reconstruction of anterior cruciate ligament

Current artificial ligaments based on polyethylene terephthalate (PET) are associated with some disadvantages due to their hydrophobicity and low biocompatibility. In this study, we aimed to modify the surface of PET using polyethylene glycol (PEG)-terminated polystyrene (PS)-linoleic nanoparticles (PLinaS-g-PEG-NPs). We accomplished that BMP-2 in two different concentrations encapsulated in nanoparticles with an efficiency of 99.71 ± 1.5 and 99.95 ± 2.8%. While the dynamic contact angle of plain PET surface reduced from 116° to 115° after a measurement periods of 10 s, that of PLinaS-g-PEG-NPs modified PET from 80° to 17.5° within 0.35 s. According to in vitro BMP2 release study, BMP-2 was released 13.12 ± 1.76% and 45.47 ± 1.78% from 0.05 and 0.1BMP2-PLinaS-g-PEG-NPs modified PET at the end of 20 days, respectively. Findings from this study revealed that BMP2-PLinaS-g-PEG-NPs has a great potential to improve the artificial PET ligaments, and could be effectively applied for ACL reconstruction.

Electrospun nanofibers containing chitosan-stabilized bovine serum albumin nanoparticles for bone regeneration

Bone tissue engineering is becoming a key approach in bone repair and regeneration. In the present study, we fabricated a nanofiber scaffold containing chitosan-stabilized bovine serum albumin (BSA) nanoparticles for the delivery of abaloparatide and aspirin (ASA). The chitosan-stabilized BSA nanoparticles acted as a release barrier for the encapsulated abaloparatide. Polymeric nanofibers were produced by electrospinning from a mixture of abaloparatide-loaded nanoparticles, ASA, poly(ε-caprolactone) (PCL), and nanohydroxyapatite (n-HA). The nanoparticle and nanofiber scaffolds were characterized in terms of their morphology, construction, surface hydrophilicity, degradation, and drug release efficiency. In vitro osteogenesis as well as in vitro cell adhesion, viability, and proliferation were determined to assess their osteoinductive activity. The results showed that the drugs were successfully encapsulated in the scaffolds. Most of the ASA was released within seven days, whereas abaloparatide was released for more than 30 days. The dual-drug-loaded nanofiber scaffolds enhanced the proliferation and osteogenic differentiation of osteoblasts. These findings indicate that electrospun nanofibers containing chitosan-stabilized BSA nanoparticles may be useful in bone tissue engineering.

Development, Optimization, and Pharmacokinetics Study of Bufalin/Nintedanib Co-loaded Modified Albumin Sub-microparticles Fabricated by Coaxial Electrostatic Spray Technology

Coaxial electrostatic spray technology has received extensive attention in fabricating micro/nanoparticles for drug delivery. However, there are few reports on applying this technology in preparing albumin nanoparticles. In this study, the bufalin (BF) and nintedanib (NDNB) co-loaded ursodeoxycholic acid and p-biguanides benzoic acid decorated albumin sub-microparticles (BN-DUB subMPs) were fabricated by coaxial electrostatic spray technology and optimized by central composite design. Five percent of albumin (contained 0.7% polyethylene oxide) solution was selected as the shell solution which ejected through outer axis with the flow rate of 0.07 mm/min, while the core solution which contained by BF and NDNB ethanol solution was ejected through inner axis with the flow rate of 0.05 mm/min. In vitro cell studies revealed that the modified albumin possessed good biocompatibility. What's more, the BN-DUB subMPs enhanced the inhibitory effect on the growth of LLC cells efficiently. The pharmacokinetics study showed that the t_1/2 and AUC_0-t of BN-DUB subMPs increased significantly compared with that of the drug solution, which indicated the improved in vivo stability of modified albumin nanoparticles. Thus, this study provided a novel and simple technical platform for the development of albumin-based drug carriers.

PLGA Core-Shell Nano/Microparticle Delivery System for Biomedical Application

Core-shell particles are very well known for their unique features. Their distinctive inner core and outer shell structure allowed promising biomedical applications at both nanometer and micrometer scales. The primary role of core-shell particles is to deliver the loaded drugs as they are capable of sequence-controlled release and provide protection of drugs. Among other biomedical polymers, poly (lactic-co-glycolic acid) (PLGA), a food and drug administration (FDA)-approved polymer, has been recognized for the vehicle material. This review introduces PLGA core-shell nano/microparticles and summarizes various drug-delivery systems based on these particles for cancer therapy and tissue regeneration. Tissue regeneration mainly includes bone, cartilage, and periodontal regeneration.

Nanotechnology for the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) affects the central nervous system (CNS) and there is currently no treatment with the potential for rehabilitation. Although several clinical treatments have been developed, they are still at an early stage and have not shown success in repairing the broken fiber, which prevents cellular regeneration and integral restoration of motor and sensory functions. Considering the importance of nanotechnology and tissue engineering for neural tissue injuries, this review focuses on the latest advances in nanotechnology for SCI treatment and tissue repair. The PubMed database was used for the bibliographic survey. Initial research using the following keywords "tissue engineering and spinal cord injury" revealed 970 articles published in the last 10 years. The articles were further analyzed, excluding those not related to SCI or with results that did not pertain to the field of interest, including the reviews. It was observed that a total of 811 original articles used the quoted keywords. When the word "treatment" was added, 662 articles were found and among them, 529 were original ones. Finally, when the keywords "Nanotechnology and spinal cord injury" were used, 102 articles were found, 65 being original articles. A search concerning the biomaterials used for SCI found 700 articles with 589 original articles. A total of 107 articles were included in the discussion of this review and some are used for the theoretical framework. Recent progress in nanotechnology and tissue engineering has shown promise for repairing CNS damage. A variety of in vivo animal testing for SCI has been used with or without cells and some of these in vivo studies have shown successful results. However, there is no translation to humans using nanotechnology for SCI treatment, although there is one ongoing trial that employs a tissue engineering approach, among other technologies. The first human surgical scaffold implantation will elucidate the possibility of this use for further clinical trials. This review concludes that even though tissue engineering and nanotechnology are being investigated as a possibility for SCI treatment, tests with humans are still in the theoretical stage. Impact statement Thousands of people are affected by spinal cord injury (SCI) per year in the world. This type of lesion is one of the most severe conditions that can affect humans and usually causes permanent loss of strength, sensitivity, and motor function below the injury site. This article reviews studies on the PubMed database, assessing the publications on SCI in the study field of tissue engineering, focusing on the use of nanotechnology for the treatment of SCI. The review makes an evaluation of the biomaterials used for the treatment of this condition and the techniques applied for the production of nanostructured biomaterials.

Technological Approaches for Improving Vaccination Compliance and Coverage

Vaccination has been well recognised as a critically important tool in preventing infectious disease, yet incomplete immunisation coverage remains a major obstacle to achieving disease control and eradication. As medical products for global access, vaccines need to be safe, effective and inexpensive. In line with these goals, continuous improvements of vaccine delivery strategies are necessary to achieve the full potential of immunisation. Novel technologies related to vaccine delivery and route of administration, use of advanced adjuvants and controlled antigen release (single-dose immunisation) approaches are expected to contribute to improved coverage and patient compliance. This review discusses the application of micro- and nano-technologies in the alternative routes of vaccine administration (mucosal and cutaneous vaccination), oral vaccine delivery as well as vaccine encapsulation with the aim of controlled antigen release for single-dose vaccination.

Electrospraying: Possibilities and Challenges of Engineering Carriers for Biomedical Applications-A Mini Review

Electrospraying, a liquid atomization-based technique, has been used to produce and formulate micro/nanoparticular cargo carriers for various biomedical applications, including drug delivery, biomedical imaging, implant coatings, and tissue engineering. In this mini review, we begin with the main features of electrospraying methods to engineer carriers with various bioactive cargos, including genes, growth factors, and enzymes. In particular, this review focuses on the improvement of traditional electrospraying technology for the fabrication of carriers for living cells and providing a suitable condition for gene transformation. Subsequently, the major applications of the electrosprayed carriers in the biomedical field are highlighted. Finally, we finish with conclusions and future perspectives of electrospraying for high efficiency and safe production.