Preliminary in vivo magnetofection data using magnetic calcium phosphate nanoparticles immobilizing DNA and iron oxide nanocrystals

The data reported herein are in association with our research article entitled "Rapid one-pot fabrication of magnetic calcium phosphate nanoparticles immobilizing DNA and iron oxide nanocrystals using injection solutions for magnetofection and magnetic targeting" (Shubhra et al. 2017) [1]. This article reports morphological and gene delivery (in vitro and preliminary in vivo) data of those calcium phosphate (CaP) naonparticles (NPs) with various iron oxide (IO) contents, named as CaP-Fe(1), CaP-Fe(2), CaP-Fe(3), CaP-Fe(4), and CaP-Fe(5), which were prepared via coprecipitation in supersaturated CaP solutions with nominal Fe concentrations 6.97, 13.94, 27.87, 55.74, and 139.35 μg/mL, respectively. Morphological data of four different NPs: CaP-Fe(1), CaP-Fe(2), CaP-Fe(4), and CaP-Fe(5) are shown here. Data of the luciferase reporter gene expression assay show the effects of the coprecipitation time and the dosage of the CaP-Fe(3) NPs on gene expression levels of CHO-K1 cells transfected by the NPs without external magnetic field. It is demonstrated using digital and microscopic images that the CaP-Fe(3) NPs localize near the periphery of the external magnet that was placed under the cell culture plate. Using the CaP-Fe(3) NPs, animal experiments were conducted to obtain preliminary in vivo magnetofection data

Cefazolin-containing poly(ε-caprolactone) sponge pad to reduce pin tract infection rate in rabbits

AbstractIn our previous study, a fibroblast growth factor-2 (FGF-2)–apatite composite layer coated on titanium screws effectively prevented pin tract infection in rabbits because of enhanced wound healing; however, the FGF-2–apatite composite layers did not completely prevent pin tract infection. Thus, we recently developed a poly(ε-caprolactone) (PCL) sponge pad embedded with cefazolin sodium (+CEZ), which has a fast-acting bactericidal effect. The pad is placed on the skin around the screws. The purpose of this study was to determine the anti-infective efficacy of the +CEZ pad on the pin–skin interface of the FGF-2–apatite-coated titanium screws. The +CEZ pads were prepared by mixing PCL and CEZ in 1,4-dioxane, followed by freeze-drying and compaction. They were analyzed regarding their surface structure, in vitro CEZ release profile, and bactericidal activity. The FGF-2–apatite-coated screws were implanted percutaneously in bilateral rabbit proximal tibial metaphyses—with and without the +CEZ pad—for 4 weeks (n = 20). The + CEZ pads consisted of a porous matrix of PCL in which CEZ was embedded. The CEZ-release profile showed an initial burst on Day 1 and a sustained release lasting for 30 days. The +CEZ pad retained its bactericidal activity against Staphylococcus aureus after preincubation on an agar plate for 7 days. Based on visual inspection, the pin tract infection rate was successfully reduced from 72.2% to 15.0% with the +CEZ pad (p < 0.05), which reduced the bacterial count, especially S. aureus (p < 0.05). The histological inflammation rate of the soft tissues was also significantly lower with the +CEZ pad than without it (p < 0.05). The pin tract infection rate was reduced to one-fifth with the +CEZ pad. Using it as described improves infection resistance during percutaneous implantation

Enhanced wound healing associated with Sharpey’s fiber-like tissue formation around FGF-2-apatite composite layers on percutaneous titanium screws in rabbits

BACKGROUND:Pin-tract infections are the most common complications of external fixation. To solve the problem, we developed a fibroblast growth factor-2 (FGF-2)-apatite composite layer for coating titanium screws. The purpose of this study was to elucidate the mechanism of the improvement in infection resistance associated with FGF-2-apatite composite layers.METHOD:We analyzed FGF-2 release from the FGF-2-apatite composite layer and the mitogenic activity of the FGF-2-apatite composite layer. We evaluated time-dependent development of macroscopic pin-tract infection around uncoated titanium control screws (n = 10). Screws coated with the apatite layer (n = 16) and FGF-2-apatite composite layer (n = 16) were percutaneously implanted for 4 weeks in the medial proximal tibia in rabbits.RESULTS:A FGF-2-apatite composite layer coated on the screws led to the retention of the mitogenic activity of FGF-2. FGF-2 was released from the FGF-2-apatite composite layer in vitro for at least 4 days, which corresponds to a period when 30% of pin-tract infections develop macroscopically in the percutaneous implantation of uncoated titanium control screws. The macroscopic infection rate increased with time, reaching a plateau of 80-90% within 12 days. This value remained unchanged until 4 weeks after implantation. The screws coated with an FGF-2-apatite composite layer showed a significantly higher wound healing rate than those coated with an apatite layer (31.25 vs. 6.25%, p < 0.05). The interfacial soft tissue that bonded to the FGF-2-apatite composite layer is a Sharpey\u27s fiber-like tissue, where collagen fibers are inclined at angles from 30 to 40° to the screw surface. The Sharpey\u27s Wber-like tissue is rich in blood vessels and directly bonds to the FGF-2-apatite composite layer via a thin cell monolayer (0.8-1.7 μm thick).CONCLUSION:It is suggested that the enhanced wound healing associated with the formation of Sharpey\u27s fiber-like tissue triggered by FGF-2 released from the FGF-2-apatite composite layer leads to the reduction in the pin-tract inflammation rate

バイオミメティックホウ ニ ヨル ナノアパタイト コウブンシ センイ フクゴウタイ ノ チョウセイ

京都大学0048新制・課程博士博士(工学)甲第9536号工博第2122号新制||工||1231(附属図書館)UT51-2002-G294京都大学大学院工学研究科材料化学専攻(主査)教授 小久保 正, 教授 平尾 一之, 教授 岩田 博夫学位規則第4条第1項該当Doctor of EngineeringKyoto UniversityDA

Biological modification of tooth surface by laser-based apatite coating techniques

Background: Development of new clinical regenerative procedures is needed for the reconstruction of the connective tissue attachment lost to periodontal disease. Apatite coating on the affected root surfaces could improve root surface biocompatibility and promote the reestablishment of connective tissue attachment. Highlight: We developed two novel techniques that use laser light for coating the tooth surface with apatite. In the laser-assisted biomimetic (LAB) process, a tooth substrate was placed in a supersaturated calcium phosphate solution and irradiated for 30 min with low-energy pulsed laser light. Due to the laser-assisted pseudo-biomineralization, a submicron-thick apatite film was created on the laser-irradiated tooth surface. Furthermore, we created a fluoride-incorporated apatite film on the tooth surface using the LAB process and demonstrated its antibacterial activity against Streptococcus mutans. In the laser-induced forward transfer with optical stamp (LIFTOP) process, a thin apatite film loaded with the cell-adhesion protein, fibronectin, was prepared beforehand as a raw material on the optical stamp (carbon- and polydimethylsiloxane-coated support) by a conventional biomimetic process. After irradiation with a single laser pulse, the film (microchip) was transferred onto a tooth substrate via laser ablation of the carbon sacrificial layer. The LIFTOP process requires only a short processing time and has a minimal heat effect on the film; thus, the film exhibits cell adhesion activity even after the LIFTOP process. Conclusion: The LAB and LIFTOP processes have the potential as novel tools for tooth surface modification in the treatment of periodontal disease

Technique for simple apatite coating on a dental resin composite with light-curing through a micro-rough apatite layer

Tooth root surfaces restored with dental resin composites exhibit inferior biocompatibility. The objective of this study was to develop a simple technique for coating apatite onto a resin composite to improve its surface biocompatibility. First, we fabricated a polymer film coated with a micro-rough apatite layer and pressed it (coating-side down) onto a viscous resin composite precursor. As a result of light-induced curing of the precursor through the overlaid film, the micro-rough apatite layer was integrated with the resin composite and, thus, transferred from the polymer film surface to the cured resin composite surface as a result of the difference in interfacial adhesion strength. The transferred apatite layer attached directly to the cured resin composite without any gaps at the microscopic level. The adhesion between the apatite layer and the cured resin composite was so strong that the layer was not peeled off even by a tape-detaching test. The flexural strength of the resulting apatite-coated resin composite was comparable to that of the clinically used resin composite while satisfying the ISO requirement for dental polymer-based restorative materials. Furthermore, the apatite-coated resin composite showed better cell compatibility than the uncoated resin composite. The present apatite coating technique is well suited for dental treatment because the coating is applied during a conventional light curing procedure through simple utilization of the apatite-coated polymer film in place of an uncoated film. The proposed technique represents a practical evolution in dental treatment using light-curing resin composites, although further in vitro and in vivo studies are needed

Laser-Induced Forward Transfer with Optical Stamp of a Protein-Immobilized Calcium Phosphate Film Prepared by Biomimetic Process to a Human Dentin

The rapid and area-specific printing of calcium phosphate with superior biocompatibility and osteoconductivity is a useful technique for the surface functionalization of biomedical devices. We recently demonstrated the laser-induced forward transfer (LIFT) of a brittle calcium phosphate film onto a soft and shock-absorbing polydimethylsiloxane (PDMS) substrate. In this work, a new LIFT using an optically transparent PDMS-coated stamp, which we hereafter call LIFT with optical stamp (LIFTOP), was introduced to achieve the transfer of brittle films to harder substrates. Cell adhesion protein fibronectin-immobilized calcium phosphate films (Fn-CaP) were prepared on the optical stamp through a biomimetic process. Then, the irradiation of a single laser pulse transferred the Fn-CaP film from the optical stamp onto relatively hard substrates, polyethylene terephthalate and human dentin. As a result of this LIFTOP process, Fn-CaP microchips with a shape corresponding to the laser beam spot were printed on the substrates. Cross-sectional observation of the interface between the Fn-CaP microchip and the dentin substrate revealed good attachment between them without obvious gaps for the most part