High-performance Hydroxyapatite Research Articles

Novel fabrication of marizomib-loaded chitosan-coated hydroxyapatite nanocarriers as a promising system for effective treatment of ovarian cancer

Cancer therapy might benefit significantly from nanotechnology. These nano-drug delivery systems (NDDS) have been established to improve the therapeutic benefits of anticancer medications by enhancing their bioavailability, degradation, and biocompatibility. One of the most promising NDDS for cancer therapy is high-performance hydroxyapatite (HA) nanoparticles, which have many advantages. The metabolite marizomib inhibits tumor cell growth and progression, functioning as a biochemical inhibitor in many malignancies. However, this substance’s low bioavailability is the most significant problem with its use. In this work, a pH-sensitive biopolymer was employed to encapsulate HA nanoparticles with chitosan to increase marizomib’s (MARI) efficacy and bioavailability. The sol-gel process was used to fabricate HA nanoparticles for this purpose. It was then coated with chitosan before encasing the marizomib drug in the nanocarrier, which was done under controlled circumstances. The newly fabricated nanoparticles effectively kill ovarian A2780 cancer cells and induce apoptosis. The morphological examination of the cancer cells was examined by AO/EB and DAPI staining methods. Further, the cell uptake was measured by the flow cytometry methods, and the result shows the nanoparticles were effectively uptake the cancer cells under different incubation times. In principle, nanoparticles have great potential for future pre-clinical applications in treating ovarian cancer cells and suppressing other types of tumors.

In vitro evaluation of curcumin-loaded chitosan-coated hydroxyapatite nanocarriers as a potential system for effective treatment of cancer

Nanotechnology has many potential applications in cancer treatment. For example, nano-drug delivery systems (NDDS) with high bioavailability, biodegradability, and biocompatibility have been developed, in order to increase the therapeutic effects of anticancer drugs. Among these NDDS, high-performance hydroxyapatite (HA) nanoparticles are rapidly advancing in the targeted cancer treatment due to their numerous benefits. Curcumin is an herbal metabolite that acts as a chemical inhibitor through the inhibition of tumor cells and the progression of many cancers. However, the poor bioavailability of curcumin is the most important challenge in using this substance. In this study, HA nanoparticles coated by chitosan were used as a pH-sensitive biopolymer to improve the efficiency and bioavailability of curcumin. For this purpose, HA nanoparticles were first synthesized by the sol-gel method. Then, a layer of chitosan was coated on it, and the curcumin drug was encapsulated in the nanocarrier, under controlled conditions. Techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the nanocarriers. In the second part, nano-drugs prepared by various bioassays were examined. For this purpose, the rate of cytotoxicity by the methyl-thiazol-tetrazolium (MTT) assay and the rate of apoptosis induction by the acridine orange and ethidium bromide (AO/EB) staining method on the brain carcinoma U87MG cell line were investigated.

High performance hydroxyapatite ceramics and a triply periodic minimum surface structure fabricated by digital light processing 3D printing

High performance hydroxyapatite (HA) ceramics with excellent densification and mechanical properties were successfully fabricated by digital light processing (DLP) three-dimensional (3D) printing technology. It was found that the sintering atmosphere of wet CO2 can dramatically improve the densification process and thus lead to better mechanical properties. HA ceramics with a relative density of 97.12% and a three-point bending strength of 92.4 MPa can be achieved at a sintering temperature of 1300 , which makes a solid foundation for application ℃ in bone engineering. Furthermore, a relatively high compressive strength of 4.09 MPa can be also achieved for a DLP-printed p-cell triply periodic minimum surface (TPMS) structure with a porosity of 74%, which meets the requirement of cancellous bone substitutes. A further cell proliferation test demonstrated that the sintering atmosphere of wet CO2 led to improve cell vitality after 7 days of cell culture Moreover, with the possible benefit from the bio-inspired structure, the 3D-printed TPMS structure significantly improved the cell vitality, which is crucial for early osteogenesis and osteointegration.

High-performance hydroxyapatite chromatography of integral membrane proteins and water-soluble proteins in complex with sodium dodecyl sulphate

Integral membrane proteins from human erythrocytes were fractionated in the presence of sodium dodecyl sulphate (SDS) on four types of high-performance hydroxyapatite columns. A column of 2-μm sintered hydroxyapatite beads from Asahi Optical (Tokyo, Japan) gave the best resolution. With this column, glycophorin was eluted early in a gradient of increasing sodium phosphate buffer concentration, the glucose transporter was eluted later in two zones, one of which contained this protein alone, and the anion transporter was eluted last. Water-soluble proteins applied in complex with SDS also separated reasonably well upon elution. The water-soluble proteins and the membrane proteins were all eluted mainly in the order of increasing polypeptide length, but with considerable individual variation. SDS-polypeptide complexes are probably adsorbed onto hydroxyapatite by the interaction of positively charged amino acid side groups with phosphate ions (at P-sites) and of negatively charged amino acid side groups and polypeptide-bound dodecyl sulphate anions with calcium ions (at C-sites). As a rule, the number of charged side groups and dodecyl sulphate anions, and thus the number of binding sites, increases with the polypeptide chain length, which explains the general order of release of the polypeptides.

Selective high-performance liquid chromatographic purification of bispecific monoclonal antibodies

The recent development of improved production techniques for bispecific monoclonal antibodies (biMAbs) has significantly increased interest in specific purification procedures. In this investigation, a general high-performance liquid chromatographic (HPLC) purification method is proposed that allows highly purified biMAbs to be obtained from mouse ascites fluid containing a mixture of different antibodies, i.e., parental MAbs, active biMAb and a mixture of randomly assembled heavy and light chains. Proteins from ascites fluid were precipitated with ammonium sulphate and applied to a high-performance protein A column to separate the total immunoglobulin fraction. BiMAbs were isolated from other immunoglobulins by two subsequent passages through a high-performance hydroxyapatite (HPHT) column. This purification protocol combines specificity of protein A for immunoglobulin G (IgG) and high selectivity of hydroxyapatite for different IgG idiotypes. All purification steps were performed rapidly and reliably by HPLC. This method was applied to the purification of six different biMAbs with consistently high yields, purity and homogeneity. This general purification method may prove extremely valuable when highly pure preparation of biMAbs is required, as for in vivo use.

Simultaneous Separation of β-Lactamase Isoenzymes by High Performance Hydroxyapatite Chromatography with Selective Postcolumn Enzymatic Reaction

Simultaneous Separation of β-Lactamase Isoenzymes by High Performance Hydroxyapatite Chromatography with Selective Postcolumn Enzymatic Reaction

Mitogenic properties of two distinct forms of toxic shock syndrome toxin‐1 separated on hydroxyapatite by high‐performance liquid chromatography

The homogeneity of a purified staphylococcal toxic shock syndrome toxin-1 (TSST-1) was tested by high-performance methods. This preparation was homogenous in ion-exchange chromatography and isoelectric focusing (pI = 7.4), but was resolved into two distinct peaks by high-performance hydroxyapatite chromatography. Both components, TSST-1hA and TSST-1hB had similar molecular weights (22 kD) and amino acid compositions. TSST-1 did not dimerize or polymerize upon heating at 60 degrees C for 30 min or in solutions with pH varying from 4.0 to 8.5. TSST-1hA and TSST-1hB showed similar immunological reactivity to native TSST-1 goat polyclonal antibodies. TSST-1hA and TSST-1hB as well as staphylococcal enterotoxin A and staphylococcal exfoliative toxin were potent mitogens in lymphocyte proliferation assays. The lymphocyte proliferative response to 10 pg of TSST-1hB was comparable to a response elicited by 10 ng of TSST-1hA, suggesting that the former component is a more potent mitogen. Rabbit or goat polyclonal antibodies to native TSST-1 efficiently neutralized both TSST-1 components. Heat treatment at 80 degrees C for 15 min had minimal or no effect on the mitogenic properties of TSST-1hA and TSST-1hB.

Protein a, hydroxyapatite and diethylaminoethyl: Evaluation of three procedures for the preparative purification of monoclonal antibodies by high-perfomance liquid chromatography

Three rapid, reproducible and feasible monoclonal antibody purification procedures by means of high-performance liquid chromatography have been evaluated. The stationary phases employed were high-performance hydroxyapatite, high-performance Protein A and high-performance anion-exchange resin. The purity of the final immunoglobulin preparations was determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis under reducing conditions and, subsequently, by high-performance gel permeation chromatography. The immunoreactivity of purified monoclonal antibodies was determined by the radioimmunoassay method.

High-performance hydroxyapatite chromatography of nucleic acids

High-performance hydroxyapatite chromatography of nucleic acids

High-performance hydroxyapatite chromatography of proteins

High-performance hydroxyapatite chromatography of proteins