Arg-Gly-Asp peptide functionalized poly-amino acid/ poly (p-benzamide) copolymer with enhanced mechanical properties and osteogenicity

Recent Advances in Degradable Biomedical Polymers for Prevention, Diagnosis and Treatment of Diseases

Biomedical polymers play a key role in preventing, diagnosing, and treating diseases, showcasing a wide range of applications. Their unique advantages, such as rich source, good biocompatibility, and excellent modifiability, make them ideal biomaterials for drug delivery, biomedical imaging, and tissue engineering. However, conventional biomedical polymers suffer from poor degradation in vivo, increasing the risks of bioaccumulation and potential toxicity. To address these issues, degradable biomedical polymers can serve as an alternative strategy in biomedicine. Degradable biomedical polymers can efficiently relieve bioaccumulation in vivo and effectively reduce patient burden in disease management. This review comprehensively introduces the classification and properties of biomedical polymers and the recent research progress of degradable biomedical polymers in various diseases. Through an in-depth analysis of their classification, properties, and applications, we aim to provide strong guidance for promoting basic research and clinical translation of degradable biomedical polymers.

Polydopamine-Based Biomaterials in Orthopedic Therapeutics: Properties, Applications, and Future Perspectives

Polydopamine is a versatile and modifiable polymer, known for its excellent biocompatibility and adhesiveness. It can also be engineered into a variety of nanoparticles and biomaterials for drug delivery, functional modification, making it an excellent choice to enhance the prevention and treatment of orthopedic diseases. Currently, the application of polydopamine biomaterials in orthopedic disease prevention and treatment is in its early stages, despite some initial achievements. This article aims to review these applications to encourage further development of polydopamine for orthopedic therapeutic needs. We detail the properties of polydopamine and its biomaterial types, highlighting its superior performance in functional modification on nanoparticles and materials. Additionally, we also explore the challenges and future prospects in developing optimal polydopamine biomaterials for clinical use in orthopedic disease prevention and treatment.

CuSO4/H2O2induced polydopamine/polysulfobetaine methacrylate co-deposition on poly(amino acid) membranes for improved anti-protein adsorption and antibacterial activity

Stopping postoperative soft tissue adhesions is one of the most challenging clinical problems that needs to be addressed urgently to avoid secondary injury and pain to patients. Currently, membrane materials with anti-protein adsorption and antibacterial activity are recognized as an effective and promising anti-adhesion barrier to prevent postoperative adhesion and the recurrent adhesion after adhesiolysis. Herein, poly(amino acid) (PAA), which is structurally similar to collagen, is selected as the membrane base material to successfully synthesize PAA-5 membranes with excellent mechanical and degradation properties by in-situ melt polymerization and hot-melt film-forming technology. Subsequently, the co-deposition of polydopamine/polysulfobetaine methacrylate (PDA/PSBMA) coatings induced by CuSO4/H2O2on PAA-5 membranes results in the formation of PDC-5S and PDC-10S, which exhibit excellent hemocompatibility, protein antifouling properties, and cytocompatibility. Additionally, PDC-5S and PDC-10S demonstrated significant antibacterial activity againstEscherichia coliandStaphylococcus aureus, with an inhibition rate of more than 90%. As a result, this study sheds light on newly discovered PAA membranes with anti-protein adsorption and antibacterial activity can sever as one of the promising candidates for the prevention of postoperative peritoneum adhesions.

Enhancing osteoblast proliferation and bone regeneration by poly (amino acid)/selenium-doped hydroxyapatite

Among various biomaterials employed for bone repair, composites with good biocompatibility and osteogenic ability had received increasing attention from biomedical applications. In this study, we doped selenium (Se) into hydroxyapatite (Se-HA) by the precipitation method, and prepared different amounts of Se-HA-loaded poly (amino acid)/Se-HA (PAA/Se-HA) composites (0, 10 wt%, 20 wt%, 30 wt%) byin-situmelting polycondensation. The physical and chemical properties of PAA/Se-HA composites were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and their mechanical properties. XRD and FT-IR results showed that PAA/Se-HA composites contained characteristic peaks of PAA and Se-HA with amide linkage and HA structures. DSC and TGA results specified the PAA/Se-HA30 composite crystallization, melting, and maximum weight loss temperatures at 203.33 °C, 162.54 °C, and 468.92 °C, respectively, which implied good thermal stability. SEM results showed that Se-HA was uniformly dispersed in PAA. The mechanical properties of PAA/Se-HA30 composites included bending, compressive, and yield strengths at 83.07 ± 0.57, 106.56 ± 0.46, and 99.17 ± 1.11 MPa, respectively. The cellular responses of PAA/Se-HA compositesin vitrowere studied using bone marrow mesenchymal stem cells (BMSCs) by cell counting kit-8 assay, and results showed that PAA/Se-HA30 composites significantly promoted the proliferation of BMSCs at the concentration of 2 mg ml-1. The alkaline phosphatase activity (ALP) and alizarin red staining results showed that the introduction of Se-HA into PAA enhanced ALP activity and formation of calcium nodule. Western blotting and Real-time polymerase chain reaction results showed that the introduction of Se-HA into PAA could promoted the expression of osteogenic-related proteins and mRNA (integrin-binding sialoprotein, osteopontin, runt-related transcription factor 2 and Osterix) in BMSCs. A muscle defect at the back and a bone defect at the femoral condyle of New Zealand white rabbits were introduced for evaluating the enhancement of bone regeneration of PAA and PAA/Se-HA30 composites. The implantation of muscle tissue revealed good biocompatibility of PAA and PAA/Se-HA30 composites. The implantation of bone defect showed that PAA/Se-HA30 composites enhanced bone formation at the defect site (8 weeks), exhibiting good bone conductivity. Therefore, the PAA-based composite was a promising candidate material for bone tissue regeneration.

Effect of controlled surface roughness and biomimetic coating on titanium implants adhesion to the bone: An experiment animal study

Introduction

Laser micromachining of titanium and its alloys can create micro-grooves with sizes similar to cell diameter of about 10 μm. Its coating with arginine-glycine-aspartic acid (RGD) may enhance cellular spreading and adhesion. This study aimed to evaluate the effect of laser micro-grooving and laser micro-grooving combined with RGD coating on the strength of the dental implants/bone interface using destructive mechanical pullout testing in experimental animals.

Materials and methods

In this study, the test groups consisted of 1.5-mm diameter, 5-mm long laser-grooved and laser-grooved/RGD coated titanium alloy (Ti-6Al-4 V) rods, and the control group included plain titanium alloy (Ti-6Al-4 V) rods. These rods were implanted in the mandibles of New Zealand white rabbits for 2, 4, and 6 weeks. After sacrifice, the test and control specimens were retrieved for mechanical pullout testing. The DMA 7-e was used to pull the titanium rods out of the bone, the probe position was plotted versus time graph to monitor the test progression, and the static modulus versus time graph was viewed; such graphs was then transformed into tables. The results were analyzed using the Mann-Whitney test.

Results

The laser-grooved/RGD coated rods had significantly higher pull-out strength than the laser-grooved and control rods. Additionally, the laser-grooved rods had significantly higher pull-out strength than control rods.

Conclusion

Two novel surface treatments were used: laser micro-grooving and tri peptide RGD coating, both of which had different effects on the dental implant interface. Laser grooving improved peri-implant bone healing, whereas RGD coating facilitated earlier bone-implant adhesion and better mineralization.

Temozolomide and chloroquine co-loaded mesoporous silica nanoparticles are effective against glioma

The past decades have witnessed great progress in nanoparticle-based cancer-targeting drug delivery systems, but their therapeutic potentials is yet to be fully exploited. In this research, temozolomide (TMZ) and chloroquine (CQ) were loaded into the mesoporous silica nanoparticles (MSNs), the surface was coated with polydopamine (PDA), and the complex was coupled with arginine-glycine-aspartic (RGD) to successfully prepare TMZ/CQ@MSN-RGD. RGD-MSNs accumulated more in the cell and tumor models than in unmodified MSNs in the in vitro and in vivo experiments and can directly induce apoptosis and autophagy in tumor cells. In addition, TMZ/CQ@MSN-RGD therapy enhanced the apoptosis effect of the RGD-MSNs in glioma. Therefore, the combination of autophagy inhibitor with chemotherapy drugs in nanocarriers may promote therapeutic efficacy in treating glioma.

Nanoparticle delivery of TFOs is a novel targeted therapy for HER2 amplified breast cancer

PURPOSE

The human EGFR2 (HER2) signaling pathway is one of the most actively studied targets in cancer transformation research. Ttriplex-forming oligonucleotides (TFOs) activate DNA damage and induce apoptosis. We aim to encapsulate TFO-HER2 with nano-particle ZW-128 to suppress breast cell growth in vitro and in vivo.

EXPERIMENTAL DESIGN

We designed a set of TFO fragments targeting HER2 and verified their effectiveness. We encapsulated TFO-HER2 in ZW-128 to form nano-drug TFO@ZW-128. Cell counting kit 8, flow cytometry, and western blotting were used to evaluate the effect of TFO@ZW-128 on cell proliferation and the expressions of related proteins. The ant-itumor effect of TFO@ZW-128 was evaluated in vivo using nude mice breast cancer model.

RESULTS

TFO@ZW-128 had efficient cellular uptake in amplified HER2 breast cancer cells. TFO@ZW-128 showed an 80-fold increase in TFO utilization compared with TFO-HER2 in the nude mouse breast cancer model. Meanwhile, TFO@ZW-128 dramatically inhibited the growth of HER2-overexpressing tumors compared with TFO-HER2 (P < 0.05). Furthermore, TFO@ZW-128-induced cell apoptosis was in a p53-independent manner.

CONCLUSIONS

In this study, we designed nano-drug TFO@ZW-128, which has proven effective and non-toxic in targeted therapy for ectopic HER2-expressing tumors.