Internalization of (bis)phosphonate-modified cellulose nanocrystals by human osteoblast cells

Abstract

Covalent conjugation of (bis)phosphonate group-containing molecules, sodium Alendronate (Aln) and 3-AminoropylPhosphoric Acid (ApA), to Cellulose nanocrystals (CNCs) was performed via oxidation/Shiff-base reaction. Further fluorescent labelling with Rhodamine B Iso ThioCyanate (RBITC) was performed to follow CNCs interaction and potential internalization with/in human osteoblasts by confocal microscopy. Complementary analyses were applied to identify the conjugation (Atenuated Total Reflectance-Fourier Transform Infrared and UV-VIS spectroscopies), physico-chemical (Dynamic Light Scattering and Nanoparticle Tracking Analysis) and morphological (Transmission Electron Microscopy) features of native and ApA/Aln-modified CNCs in physiologically relevant environments (Phosphate Buffer Saline, Advanced Dulbecco's Modified Eagle Medium). While conjugation did not affect the CNCs' size, the RBITC-labelling promotes their aggregation. Faster (1 h vs. 2 h) uptake by osteoblasts of RBITCCNCoxAln, compared to RBITC-CNCoxApA, and no-internalization (in 24 h) of native RBITTC-CNC, indicate a higher affinity of Aln-modified CNCs to the cells, while all CNCs (in 0.25-0.06 wt%) promote the cell growth. Aln/Apa-modified CNCs shows high potential in drug-delivery for bone therapies, and theranostics.

Bacterial Cellulose: Production, Modification and Perspectives in Biomedical Applications

“…Nanocellulose materials attract significant attention in biomedical materials research [93,94,95] devoted to tissue engineering [96], cell [97] and gene therapy [98], diagnostic [99] and controlled delivery [100], mainly related to their nano-features and properties arising from them. For BC, there is also ultra-high purity and net-like morphology similar to (human) collagen as a biomimetic feature, which facilitates applications such as artificial skin (Figure 8a), vascular grafts (Figure 8b), tissue-engineering scaffolds, dental implants, medical pads, artificial bone and cartilage, delivery of drugs, proteins and hormones [101].…”

Nanoporous Metal Phosphonate Hybrid Materials as a Novel Platform for Emerging Applications: A Critical Review

“…The construction of novel porous materials with well-designed network topologies is one of the most challenging directions in various research fields owing to the great potential of these materials in the booming bio-applications including drug delivery, [192][193][194][195][196] and bioceramics. [197,198] Excitingly, the impressive ability of porous metal phosphonate hybrid materials with predefined functionality and well-defined porosity as well as valuable biocompatibility make them stand out from all kinds of porous materials, showing the huge promise to be a novel category of biomaterials.…”

“…Significantly, bisphosphonates show great promise to be stable and efficient analogues of pyrophosphate, in which the POP bonds are replaced by PCP bonds, making them more stable and less susceptible to be attacked by enzymes. [192] Kokol's group reported the internalization of (bis)phosphonate-modified cellulose nanocrystals by human osteoblast cells, [193] in which phosphonate moieties played a crucial role in the treatment of osteoporosis, and they could be tethered with fluorescent molecules to successfully deliver this drug molecule for bone therapy. More recently, Zubieta and co-workers highlighted the hydrothermal synthesis of three Ca(II)-diphosphonate materials with relevance to treatment of bone disease.…”

Mechanical Properties and Cytotoxicity of Differently Structured Nanocellulose-hydroxyapatite Based Composites for Bone Regeneration Application

“…The preparation of CaO from the eggshell and its further conversion into Ca(OH) 2 , used as a calcium precursor for the preparation of the HA, was presented in our previous work [68]; the detailed preparation protocol was given in Supplementary Materials. TEMPO-mediated oxidation of the CNF was performed as previously reported elsewhere [40,69]; the detailed procedure was given in Supplementary Materials.…”

“…The diffraction patterns were recorded using CuKα radiation at a voltage of 40 kV and a current of 30 mA. The range of 2θ was chosen from 5 • to 80 • , with a step size of 0.02 and a collection time of 3 s. The average crystallite size of the synthesized HA was estimated at 2θ of 25 • , 32 • , 39 • , and 46 • using the Scherrer equation [68]:…”