A 3D-Printed Biomaterial Scaffold Reinforced with Inorganic Fillers for Bone Tissue Engineering: In Vitro Assessment and In Vivo Animal Studies.

This research aimed to substantiate the potential practicality of utilizing a matrix-like platform, a novel 3D-printed biomaterial scaffold, to enhance and guide host cells' growth for bone tissue regeneration. The 3D biomaterial scaffold was successfully printed using a 3D Bioplotter® (EnvisionTEC, GmBH) and characterized. Osteoblast-like MG63 cells were utilized to culture the novel printed scaffold over a period of 1, 3, and 7 days. Cell adhesion and surface morphology were examined using scanning electron microscopy (SEM) and optical microscopy, while cell viability was determined using MTS assay and cell proliferation was evaluated using a Leica microsystem (Leica MZ10 F). The 3D-printed biomaterial scaffold exhibited essential biomineral trace elements that are significant for biological bone (e.g., Ca-P) and were confirmed through energy-dispersive X-ray (EDX) analysis. The microscopy analyses revealed that the osteoblast-like MG63 cells were attached to the printed scaffold surface. The viability of cultured cells on the control and printed scaffold increased over time (p < 0.05); however, on respective days (1, 3, and 7 days), the viability of cultured cells between the two groups was not significantly different (p > 0.05). The protein (human BMP-7, also known as growth factor) was successfully attached to the surface of the 3D-printed biomaterial scaffold as an initiator of osteogenesis in the site of the induced bone defect. An in vivo study was conducted to substantiate if the novel printed scaffold properties were engineered adequately to mimic the bone regeneration cascade using an induced rabbit critical-sized nasal bone defect. The novel printed scaffold provided a potential pro-regenerative platform, rich in mechanical, topographical, and biological cues to guide and activate host cells toward functional regeneration. The histological studies revealed that there was progress in new bone formation, especially at week 8 of the study, in all induced bone defects. In conclusion, the protein (human BMP-7)-embedded scaffolds showed higher regenerative bone formation potential (week 8 complete) compared to the scaffolds without protein (e.g., growth factor; BMP-7) and the control (empty defect). At 8 weeks postimplantation, protein (BMP-7) significantly promoted osteogenesis as compared to other groups. The scaffold underwent gradual degradation and replacement by new bones at 8 weeks in most defects.

Synthesis and Cytotoxic Activity of 1,2,4-Triazolo-Linked Bis-Indolyl Conjugates as Dual Inhibitors of Tankyrase and PI3K.

A series of new 1,2,4-triazolo-linked bis-indolyl conjugates (15a-r) were prepared by multistep synthesis and evaluated for their cytotoxic activity against various human cancer cell lines. It was observed that they were more susceptible to colon and breast cancer cells. Conjugates 15o (IC50 = 2.04 µM) and 15r (IC50 = 0.85 µM) illustrated promising cytotoxicity compared to 5-fluorouracil (5-FU, IC50 = 5.31 µM) against the HT-29 cell line. Interestingly, 15o and 15r induced cell cycle arrest at the G0/G1 phase and disrupted the mitochondrial membrane potential. Moreover, these conjugates led to apoptosis in HT-29 at 2 µM and 1 µM, respectively, and also enhanced the total ROS production as well as the mitochondrial-generated ROS. Immunofluorescence and Western blot assays revealed that these conjugates reduced the expression levels of the PI3K-P85, ß-catenin, TAB-182, ß-actin, AXIN-2, and NF-κB markers that are involved in the ß-catenin pathway of colorectal cancer. The results of the in silico docking studies of 15r and 15o further support their dual inhibitory behaviour against PI3K and tankyrase. Interestingly, the conjugates have adequate ADME-toxicity parameters based on the calculated results of the molecular dynamic simulations, as we found that these inhibitors (15r) influenced the conformational flexibility of the 4OA7 and 3L54 proteins.

Short Antiangiogenic MMP-2 Peptide-Decorated Conjugated Linoleic Acid-Coated SPIONs for Targeted Paclitaxel Delivery in an A549 Cell Xenograft Mouse Tumor Model.

The design of targeted antiangiogenic nanovectors for the delivery of anticancer drugs presents a viable approach for effective management of nonsmall-cell lung carcinoma (NSCLC). Herein, we report on the fabrication of a targeted delivery nanosystem for paclitaxel (PTX) functionalized with a short antimatrix metalloproteinase 2 (MMP-2) CTT peptide for selective MMP-2 targeting and effective antitumor activity in NSCLC. The fabrication of the targeted nanosystem (CLA-coated PTX-SPIONs@CTT) involved coating of superparamagnetic iron-oxide nanoparticles (SPIONs) with conjugated linoleic acid (CLA) via chemisorption, onto which PTX was adsorbed, and subsequent surface functionalization with carboxylic acid groups for conjugation of the CTT peptide. CLA-coated PTX SPIONs@CTT had a mean particle size of 99.4 nm and a PTX loading efficiency of ∼98.5%. The nanosystem exhibited a site-specific in vitro PTX release and a marked antiproliferative action on lung adenocarcinoma cells. The CTT-functionalized nanosystem significantly inhibited MMP-2 secretion by almost 70% from endothelial cells, indicating specific anti-MMP-2 activity. Treatment of tumor-bearing mice with subcutaneous injection of the CTT-functionalized nanosystem resulted in 69.7% tumor inhibition rate, and the administration of the nanosystem subcutaneously prolonged the half-life of PTX and circulation time in vivo. As such, CLA-coated PTX-SPIONs@CTT presents with potential for application as a targeted nanomedicine in NSCLC management.

Surface Immobilization of Anti-VEGF Peptide on SPIONs for Antiangiogenic and Targeted Delivery of Paclitaxel in Non-Small-Cell Lung Carcinoma.

A design has been established for the surface decoration of superparamagnetic iron oxide nanoparticles (SPIONs) with anti-vascular endothelial growth factor peptide, HRH, to formulate a targeted paclitaxel (PTX) delivery nanosystem with notable tumor targetability and antiangiogenic activity. The design methodology included (i) tandem surface functionalization via coupling reactions, (ii) pertinent physicochemical characterization, (iii) in vitro assessment of drug release, anti-proliferative activity, and quantification of vascular endothelial growth factor A (VEGF-A) levels, and (iv) in vivo testing using a lung tumor xenograft mouse model. Formulated CLA-coated PTX-SPIONs@HRH depicted a size and surface charge of 108.5 ± 3.5 nm and -30.4 ± 2.3 mV, respectively, and a quasi-spherical shape relative to pristine SPIONs. Fourier transform infrared (FTIR) analysis and estimation of free carboxylic groups supported the preparation of the CLA-coated PTX-SPIONs@HRH. CLA-coated PTX-SPIONs@HRH exhibited high PTX loading efficiency (98.5%) and sustained release in vitro, with a marked dose dependent anti-proliferative activity in A549 lung adenocarcinoma cells, complimented by an enhanced cellular uptake. CLA-coated PTX-SPIONs@HRH significantly reduced secretion levels of VEGF-A in human dermal microvascular endothelial cells from 46.9 to 35.6 pg/mL compared to untreated control. A 76.6% tumor regression was recorded in a lung tumor xenograft mouse model following intervention with CLA-coated PTX-SPIONs@HRH, demonstrating tumor targetability and angiogenesis inhibition. CLA-coated PTX-SPIONs@HRH enhanced the half-life of PTX by almost 2-folds and demonstrated a prolonged PTX plasma circulation time from a subcutaneous injection (SC). Thus, it is suggested that CLA-coated PTX-SPIONs@HRH could provide a potential effective treatment modality for non-small-cell lung carcinoma as a nanomedicine.