Application Effect of Plan-do-check Action Cycle Nursing Protocol on Improving the Accuracy of Urine Specimen Collection in Newborn Female Infants.

Background: The effect of traditional disposable infant urine collectors is not ideal for female newborns. Due to the poor adhesion of the traditional urine collection bag, it does not meet the physiological and anatomical characteristics of female newborns. Therefore, it is necessary to adopt effective nursing in urine specimen collection in newborn female infants. Objective: To explore the effect of plan-do-check action cycle nursing protocol on improving the accuracy of urine specimen collection in newborn female infants. Design: This was a randomized controlled study. Setting: This study was carried out in the Department of Pediatrics, Strategic Support Force Medical Center. Participants: A total of 120 female newborns admitted to our hospital from January 2021 to June 2022 were selected and divided into a control group and a study group, with 60 cases in each group. Interventions: The control group collected urine samples by routine methods, which used the traditional disposable urine bag collection method. The study group collected urine samples using the plan-do-check action cycle nursing mode. Primary Outcome Measures: (1) success rate of urine collection, collection times, and sample contamination rate (2) cleanliness of the vaginal opening (3) satisfaction of urine collection (4) retention time of urine samples and (5) urine pondus hydrogenii values. Results: Compared to the control group, the success rate of urine collection in the study group was higher, the collection times and specimen contamination rate were significantly lower, the time for collecting urine samples in the study group was shorter, the cleanliness of female vaginal opening in the study group was significantly better, the proportion of female urine pondus hydrogenii 6-7 in the study group was significantly higher (all P < .05). Conclusion: The application of the plan-do-check action cycle management mode in the urine samples of newborn female infants can not only effectively improve the success rate of collection but also improve the cleanliness of the vaginal mouth and make the test results more accurate.

Long-term haplodeficency of DSPP causes temporomandibular joint osteoarthritis in mice.

BACKGROUND: Extracellular matrix (ECM) protein malfunction or defect may lead to temporomandibular joint osteoarthritis (TMJ OA). Dentin sialophophoprotein (DSPP) is a mandibular condylar cartilage ECM protein, and its deletion impacted cell proliferation and other extracellular matrix alterations of postnatal condylar cartilage. However, it remains unclear if long-term loss of function of DSPP leads to TMJ OA. The study aimed to test the hypothesis that long-term haploinsufficiency of DSPP causes TMJ OA. MATERIALS AND METHODS: To determine whether Dspp+/- mice exhibit TMJ OA but no severe tooth defects, mandibles of wild-type (WT), Dspp+/-, and Dspp homozygous (Dspp-/-) mice were analyzed by Micro-computed tomography (micro-CT). To characterize the progression and possible mechanisms of osteoarthritic degeneration over time in Dspp+/- mice over time, condyles of Dspp+/- and WT mice were analyzed radiologically, histologically, and immunohistochemically. RESULTS: Micro-CT and histomorphometric analyses revealed that Dspp+/- and Dspp-/- mice had significantly lower subchondral bone mass, bone volume fraction, bone mineral density, and trabecular thickness compared to WT mice at 12 months. Interestingly, in contrast to Dspp-/- mice which exhibited tooth loss, Dspp+/- mice had minor tooth defects. RNA sequencing data showed that haplodeficency of DSPP affects the biological process of ossification and osteoclast differentiation. Additionally, histological analysis showed that Dspp+/- mice had condylar cartilage fissures, reduced cartilage thickness, decreased articular cell numbers and severe subchondral bone cavities, and with signs that were exaggerated with age. Radiographic data showed an increase in subchondral osteoporosis up to 18 months and osteophyte formation at 21 months. Moreover, Dspp+/- mice showed increased distribution of osteoclasts in the subchondral bone and increased expression of MMP2, IL-6, FN-1, and TLR4 in the mandibular condylar cartilage. CONCLUSIONS: Dspp+/- mice exhibit TMJ OA in a time-dependent manner, with lesions in the mandibular condyle attributed to hypomineralization of subchondral bone and breakdown of the mandibular condylar cartilage, accompanied by upregulation of inflammatory markers.

Preparation and In Vitro Cellular Uptake Assessment of Multifunctional Rubik-Like Magnetic Nano-Assemblies.

Through self-assembly of nanoparticles into high-order and stable structures of cubic clusters, high drug-loading rubik-like magnetic nano-assemblies (MNAs), possessing folic acid targeting and strong magnetism-enhanced cellular uptake capabilities, were built. In this study, the core of the cubic drug assemblies consisted of four monodisperse superparamagnetic iron oxide nanoparticles coated with layers of oleic acid (Fe3O4@OA), simultaneously encapsulating fluorescein, and Paclitaxol (Flu-MNAs and PTX-MNAs) for imaging and therapeutic applications. To enable preferential tumor cellular uptake by the nanocarriers, the outermost layer of Fe3O4 was functionalized with the new dual-oleic acid-polyethylene glycol-folic acid polymer (FA-PEG-Lys-OA2) as a "shell." The drug carriers exhibited excellent stability and biocompatibility, and showed high drug loading and excellent magnetic response In Vitro. Furthermore, preliminary evaluations of the drug carriers with Hela cells showed effective cellular targeting capability. In addition, the cubic assemblies enhanced anticancer efficiency for Hela cells compared to bare drugs. Especially, the applied external magnetic field further improved the uptake of the vectors, and thereby enhanced the inhibitory effect. In brief, all these results suggested that cubic assemblies could serve as potential strategies for targeted anticancer therapies.

A Functional Iron Oxide Nanoparticles Modified with PLA-PEG-DG as Tumor-Targeted MRI Contrast Agent.

PURPOSE: Tumor targeting could greatly promote the performance of magnetic nanomaterials as MRI (Magnetic Resonance Imaging) agent for tumor diagnosis. Herein, we reported a novel magnetic nanoparticle modified with PLA (poly lactic acid)-PEG (polyethylene glycol)-DG (D-glucosamine) as Tumor-targeted MRI Contrast Agent. METHODS: In this work, we took use of the D-glucose passive targeting on tumor cells, combining it on PLA-PEG through amide reaction, and then wrapped the PLA-PEG-DG up to the Fe3O4@OA NPs. The stability and anti phagocytosis of Fe3O4@OA@PLA-PEG-DG was tested in vitro; the MRI efficiency and toxicity was also detected in vivo. RESULTS: These functional magnetic nanoparticles demonstrated good biocompatibility and stability both in vitro and in vivo. Cell experiments showed that Fe3O4@OA@PLA-PEG-DG nanoparticles exist good anti phagocytosis and high targetability. In vivo MRI images showed that the contrast effect of Fe3O4@OA@PLA-PEG-DG nanoparticles prevailed over the commercial non tumor-targeting magnetic nanomaterials MRI agent at a relatively low dose. CONCLUSIONS: The DG can validly enhance the tumor-targetting effect of Fe3O4@OA@PLA-PEG nanoparticle. Maybe MRI agents with DG can hold promise as tumor-targetting development in the future.

[Preparation and properties of thermosensitive in situ gel for ophthalmic formulation containing pearl hydrolyzate].

The study was designed to generate an ophthalmic thermosensitive in situ gel with improved mechanical and mucoadhesive properties that may prolong the retention time to enhance the bioavalability of pearl hydrolyzate. The gene was comprised of poloxamer 407, poloxamer188 and Carbopol 934, which were optimized by central composite design and response surface methodology. The rheological properties, transcorneal permeability, retention time and in vitro release behaviors of the optimal gel formulation were investigated. The gel was Newtonian liquid at 25 ℃ and performed as a semisolid gel with non-Newtonian liquid property with a gelation time of 13 s at 35 ℃. Compared with a conventional eye drops, the ophthalmic in situ gel exhibited a sevenfold increase in retention with a sustained release behavior, which was observed with suitable permeability coefficient at 5.58 cm·s-1. In conclusion, the new gel of pearl hydrolyzate prolonged the release duration of drug, which may decrease the frequency of administration of pearl hydrolyzate.

Effective PEGylation of Fe3O4 Nanomicelles for In Vivo MR Imaging.

A practical and effective strategy for synthesizing PEGylated Fe3O4 nanomicelles is established. In this strategy, a magnetic fluid of the Fe3O4 nanomicelles was synthesized with amphiphilic PEGylated phospholipid as surfactant and soybean oil as stabilizer under simple mechanical stirring and subsequent ultrasonication. Transmission electron microscope (TEM) measurement indicated that the sample is monodisperse spherical Fe3O4 nanoparticles with internal core size of 9 nm and external nanomicelle shell thickness of 1.5 nm. The final hydrodynamic size of the sample is 19.5 nm and its zeta potential is - 38.5 mV, suggesting good stability of the magnetic nanomicelles in water. To assess the ability of magnetic nanomicelles to escape reticuloendothelial system (RES) uptake, in vitro cell phagocytosis experiments were conducted using murine macrophages (RAW264.7). The results indicated that the PEGylation can effectively prevent the uptake of the nanomicelles by the macrophages. Using a mouse model of 4T1 breast cancer, the nanomicelles provided a good magnetic resonance imaging (MRI) capability to sensitively detect tumor by enhanced permeability and retention (EPR) effect. The PEGylated monodisperse magnetic nanomicelles would become a potential contrast agent for passive targeting diagnosis of tumor by MR imaging.

Slippery Porous-Liquid-Infused Porous Surface (SPIPS) with On-Demand Responsive Switching between "Defensive" and "Offensive" Antifouling Modes.

Slippery liquid-infused porous surfaces (SLIPS) have received widespread attention in the antifouling field. However, the reduction in antifouling performance caused by lubricant loss limits their application in marine antifouling. Herein, inspired by the skin of a poison dart frog which contains venom glands and mucus, a porous liquid (PL) based on ZIF-8 is prepared as a lubricant and injected into a silicone polyurethane (SPU) matrix to construct a new type of SLIPS for marine antifouling applications: the slippery porous-liquid-infused porous surface (SPIPS). The SPIPS consists of a responsive antifoulant-releasing switch between "defensive" and "offensive" antifouling modes to intelligently enhance the antifouling effect after lubricant loss. The SPIPS can adjust antifouling performance to meet the antifouling requirements under different light conditions. The wastage of antifoulants is reduced, thereby effectively maintaining the durability and service life of SLIPS materials. The SPIPS exhibits efficient lubricant self-replenishment, self-cleaning, anti-protein, anti-bacterial, anti-algal, and self-healing (97.48%) properties. Furthermore, it shows satisfactory 360-day antifouling performance in actual marine fields during boom seasons, demonstrating the longest antifouling lifespan in the field tests of reported SLIPS coatings. Hence, the SPIPS can effectively promote the development of SLIPS for neritic antifouling.

Squid inspired elastomer marine coating with efficient antifouling strategies: Hydrophilized defensive surface and lower modulus.

In antifouling applications for the marine industry, low surface energy coatings entail turbulent water flow to release marine biofouling, which presents a substantial challenge for antifouling in the static situation. The traditional solution is to add environmentally friendly antifouling agents, but it has the problem of exhaustion. Therefore, the low surface energy elastic antifouling coating without antifoulants has high research value. Herein, inspired by soft body and epidermal mucus of squid, the stable polyvinylpyrrolidone (PVP) hydrophilic segments were introduced to modify the polydimethylsiloxane-based polyurethane (PDMS-PU), realizing low surface energy elastomer coatings with hydrophilized defensive surface and reduced elastic modulus (<1.1 MPa). In an aqueous environment, the tailored surface exposed sufficient stable hydrophilic segments, exerting excellent antifouling performance, which improved the anti-adsorption effect on biological proteins, bacteria (antibacterial rate 95.24%) and algae (cover rate <3%). The coating exhibited excellent marine antifouling performance within 150 days and also gave a new impetus to developing an eco-friendly and sustainable solution for no-antifoulant marine antifouling applications.

Primary observation of the role of posttranslational modification of dentin sialophosphoprotein (DSPP) on postnatal development of mandibular condyle in mice.

OBJECTIVES: We aimed to observe the posttranslational role of dentin sialophosphoprotein (DSPP) on postnatal development of mandibular condyle in mice. METHODS: To explore the function of full-length DSPP, four groups of mice were employed: (1) wild type (WT) mice; (2)Dspp knockout (Dspp KO) mice; (3) mice expressing the normal DSPP transgene in the Dspp KO background (Dspp KO/normal Tg); (4) mice expressing the uncleavable full-length DSPP in the Dspp KO background (Dspp KO/D452A Tg). Firstly, Plain X-ray Radiography and Micro-computed Tomography were used to observe the condylar morphology changes of Dspp KO/D452A Tg mice in comparison with the other three groups. Then, Hematoxylin & eosin and toluidine blue staining were applied to uncover the histological changes of mandibular condylar cartilage (MCC) of Dspp KO/D452A Tg mice. To explore the function of the NH2-terminal fragments (i.e. DSP/DSP-PG), three groups of mice were employed: (1) WT mice; (2) Dspp KO mice; (3) mice expressing the NH2-terminal fragments of DSPP in the Dspp-null background (Dspp KO/DSP Tg). The former strategies were utilized to examine the differences of condylar morphology and histological structures changes within three groups of mice. RESULTS: Transgenic full-length DSPP partially maintained mandibular condylar morphology and MCC thickness of Dspp KO mice. Transgenic DSP failed to do so, but led to smaller mandibular condyle and disordered cartilage structure. CONCLUSIONS: Our observations provide insight into the role of posttranslational modification of DSPP in the postnatal development of healthy MCC and maintenance of condylar morphology.

Surface initiated atom transfer radical polymerization: access to three dimensional wavelike polymer structure modified capillary columns for online phosphopeptide enrichment.

Reversible phosphorylation is one of the most important post-translational modifications of proteins and a key regulator of cellular signaling pathways. Specific enrichment of phosphopeptides from proteolytic digests is a prerequisite for large scale identification of protein phosphorylation by mass spectrometry. Online enrichment of phosphopeptides attracts particular interests due to its automated operation, higher throughput and reproducibility, lower sample loss, and contamination. Here, we report a new type of capillary column developed using surface initiated atom transfer radical polymerization (SI-ATRP) for automated online phosphopeptide enrichment. SI-ATRP modification leads to a surface confined growth of three-dimensional wavelike polymer structure on the inner wall of capillary columns and, therefore, results in largely increased surface area. Furthermore, the noncross-linked flexible polymer chains grown by SI-ATRP create a large internal volume that allows phosphopeptides to penetrate into during enrichment and also facilitate the interaction between the numerous functional groups in the polymer chains and target phosphopeptides. Therefore, highly efficient and specific enrichment is achieved even for a low femtomole of phosphopeptides. The loading capacity is increased more than an order of magnitude compared with that obtained using conventional open tubular capillary columns. The SI-ATRP modified capillary column was successful applied in the online phosphoproteomics analysis of HepG2 cell lysate and resulted in 10 times improved phosphopeptide identification than the previously reported number. Finally, the SI-ATRP technique is compatible with a variety of functional monomers, and therefore, versatile potential applications in reverse phase, ion exchange, and affinity chromatography can be expected.

Haploinsufficiency of Dspp Gene Causes Dentin Dysplasia Type II in Mice.

Dentin dysplasia (DD) and dentinogenesis imperfecta (DGI) patients have abnormal structure, morphology, and function of dentin. DD-II, DGI-II, and DGI-III are caused by heterozygous mutations in the dentin sialophosphoprotein (DSPP) gene in humans. Evidences have shown that loss of function of DSPP in Dspp knockout mice leads to phenotypes similar to DGI-III, and that the abnormal dentinogenesis is associated with decreased levels of DSPP, indicating that DSPP haploinsufficiency may play a role in dentinogenesis. Thus, to testify the haploinsufficiency of Dspp, we used a Dspp heterozygous mouse model to observe the phenotypes in the teeth and the surrounding tissues. We found that Dspp heterozygous mice displayed dentin phenotypes similar to DD-II at the ages of 12 and 18 months, which was characterized by excessive attrition of the enamel at the occlusal surfaces, thicker floor dentin of the pulp chamber, decreased pulp volume, and compromised mineralization of the dentin. In addition, the periodontium was also affected, exhibiting apical proliferation of the junctional epithelium, decreased height and width of the alveolar bone, and infiltration of the inflammatory cells, leading to the destruction of the periodontium. Both the dental and periodontal phenotypes were age-dependent, which were more severe at 18 months old than those at 12 months old. Our report is the first to claim the haploinsufficiency of Dspp gene and a DD-II mouse model, which can be further used to study the molecular mechanisms of DD-II.

Enhanced Tumor Synergistic Therapy by Injectable Magnetic Hydrogel Mediated Generation of Hyperthermia and Highly Toxic Reactive Oxygen Species.

Nanoparticle-mediated tumor magnetic induction hyperthermia has received tremendous attention. However, it has been a challenge to improve the efficacy at 42 °C therapeutic temperatures without resistance to induced thermal stress. Therefore, we designed a magnetic hydrogel nanozyme (MHZ) utilizing inclusion complexation between PEGylated nanoparticles and α-cyclodextrin, which can enhance tumor oxidative stress levels by generating reactive oxygen species through nanozyme-catalyzed reactions based on tumor magnetic hyperthermia. MHZ can be injected and diffused into the tumor tissue due to shear thinning as well as magnetocaloric phase transition properties, and magnetic heat generated by the Fe3O4 first gives 42 °C of hyperthermia to the tumor. Fe3O4 nanozyme exerts peroxidase-like properties in the acidic environment of tumor to generate hydroxyl radicals (•OH) by the Fenton reaction. The hyperthermia promotes the enzymatic activity of Fe3O4 nanozyme to produce more •OH. Simultaneously, •OH further damages the protective heat shock protein 70, which is highly expressed in hyperthermia to enhance the therapeutic effect of hyperthermia. This single magnetic nanoparticle exerts dual functions of hyperthermia and catalytic therapy to synergistically treat tumors, overcoming the resistance of tumor cells to induced thermal stress without causing severe side effects to normal tissues at 42 °C hyperthermia.

Magnetic field activated drug release system based on magnetic PLGA microspheres for chemo-thermal therapy.

Controlled drug delivery systems have been extensively investigated for cancer therapy in order to obtain better specific targeting and therapeutic efficiency. Herein, we developed doxorubicin-loaded magnetic PLGA microspheres (DOX-MMS), in which DOX was encapsulated in the core and high contents (28.3 wt%) of γ-Fe2O3 nanoparticles (IOs) were electrostatically assembled on the surface of microsphere to ensure the high sensitivity to response of an external alternating current magnetic field (ACMF). The IOs in PLGA shell can both induce the heat effect and trigger shell permeability enhancement to release drugs when DOX-MMs was activated by ACMF. Results show that the cumulative drug release from DOX-MMs exposed to ACMF for 30 min (21.6%) was significantly higher (approximately 7 times higher) than that not exposed to ACMF (2.8%). The combination of hyperthermia and enhanced DOX release from DOX-MMS is beneficial for in vitro 4T1 breast cancer cell apoptosis as well as effective inhibition of tumor growth in 4T1 tumor xenografts. Therefore, the DOX-MMS can be optimized as powerful delivery system for efficient magnetic responsive drug release and chemo-thermal therapy.

Controlled drug release and hydrolysis mechanism of polymer-magnetic nanoparticle composite.

Uniform and multifunctional poly(lactic acid) (PLA)-nanoparticle composite has enormous potential for applications in biomedical and materials science. A detailed understanding of the surface and interface chemistry of these composites is essential to design such materials with optimized function. Herein, we designed and investigated a simple PLA-magnetic nanoparticle composite system to elucidate the impact of nanoparticles on the degradation of polymer-nanoparticle composites. In order to have an in-depth understanding of the mechanisms of hydrolysis in PLA-nanoparticle composites, degradation processes were monitored by several surface sensitive techniques, including scanning electron microscopy, contact angle goniometry, atomic force microscopy, and sum frequency generation spectroscopy. As a second-order nonlinear optical technique, SFG spectroscopy was introduced to directly probe in situ chemical nature at the PLA-magnetic nanoparticle composite/aqueous interface, which allowed for the delineation of molecular mechanisms of various hydrolysis processes for degradation at the molecular level. The best PLA-NP material, with a concentration of 20% MNP in the composite, was found to enhance the drug release rate greater than 200 times while maintaining excellent controlled drug release characteristics. It was also found that during hydrolysis, various crystalline-like PLA domains on the surfaces of PLA-nanoparticle composites influenced various hydrolysis behaviors of PLA. Results from this study provide new insight into the design of nanomaterials with controlled degradation and drug release properties, and the underlined molecular mechanisms. The methodology developed in this study to characterize the polymer-nanoparticle composites is general and widely applicable.

High-performance PEGylated Mn-Zn ferrite nanocrystals as a passive-targeted agent for magnetically induced cancer theranostics.

An effective magnetic nanocrystals (MNCs)-mediated theranostics strategy as a combination of simultaneous diagnostics and heating treatment of tumors by using magnetic resonance imaging (MRI) and alternating current magnetic field (ACMF) is successfully developed. In this strategy, we had firstly synthesized a well-established Mn-Zn ferrite MNCs coated with PEG-phospholipids (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol copolymers, DSPE-PEG2000). The monodisperse PEGylated MNCs with core-shell structure (15 nm) exhibited excellent performance, such as high magnetism of 98 emu g(-1) Fe, relaxivity coefficient (r2) of 338 mm(-1) s(-1), and specific absorption rate (SAR) value of 324 W g(-1) Fe. It was proved that the obtained MNCs with an average diameter of 48.6 nm can drastically minimize the recognition and phagocytosis of macrophages, simultaneously improve their biocompatibility in vitro. These advantages endowed them with efficient passive targeting ability in vivo for prominent tumor MRI and magnetically induced heating when exposed to ACMF, based on enhanced permeability and retention (EPR) effects. To ensure sufficient accumulation of MNCs within tumors for targeted hyperthermia, we described the use of MNCs with a well-tolerated intravenous single dose of 18 mg Fe/kg mouse body weight, achieving repeatedly injection and hyperthermia within a subcutaneous breast cell carcinoma mouse model. With an ACMF of 12 A at 390 kHz, the tumor surface sites could be heated to approximately 43 °C in 30 min based on MNCs-mediated intravenous injections. The long-lasting hyperthermia could effectively induce the apoptosis of tumor cells, inhibit the angiogenesis of tumor vessels, and finally suppress the tumor growth within a certain period of time.

Bone responses to simvastatin-loaded porous implant surfaces in an ovariectomized model.

PURPOSE: The purpose of this study was to investigate bone responses to simvastatin-loaded porous implant surfaces in an ovariectomized model. MATERIALS AND METHODS: Roughened implants were divided into a control group (n = 32), test group 1 (n = 32), and test group 2 (n = 32). Test implants were immersed into 10?7 mol/L (test group 1) or 10?6 mol/L (test group 2) simvastatin solutions for drug adsorption onto implant surfaces. Forty-eight ovariectomized rats randomly received an implant in each tibia. One, 2, 4, and 12 weeks later, the tibiae were retrieved and prepared for histomorphometric evaluation. Bone-to-implant contact and bone area around the implant were determined, and histologic observations were made. RESULTS: New bone formation on test implant surfaces was seen after 1 week, while it was seen on the control implant surface after 2 weeks. There was more bone tissue and bone-to-implant contact along the test implant surfaces than along the control implant surface. The test group 1 and test group 2 implants showed significantly greater bone area and bone-to-implant contact compared to the control implant at all observed time points (P < .05). No differences were found between the two types of test group implants after 1, 2, 4, and 12 weeks (P > .05). CONCLUSION: Simvastatin-loaded porous implant surfaces have the potential to improve implant osseointegration in an ovariectomized rat model.

Effect of strontium-substituted nanohydroxyapatite coating of porous implant surfaces on implant osseointegration in a rabbit model.

PURPOSE: This study investigated the effects of a strontium-substituted nanohydroxyapatite (Sr-HA) coating, deposited onto porous implant surfaces using an electrochemical process, on implant osseointegration in a rabbit model. MATERIALS AND METHODS: The surfaces were analyzed by field-emission scanning electron microscopy, x-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), a portable surface roughness tester, and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Thirty implants (half HA-coated and half Sr-HA-coated) were inserted into femurs of 15 rabbits. After 2, 4, and 8 weeks, the femurs were retrieved and prepared for histomorphometric evaluation. RESULTS: Microscopic examination showed a surface topography of rodlike crystals on both surfaces. XRD and FT-IR showed that the phase of the deposits was HA. No differences were found in surface roughness between the two groups. ICP-AES showed that the Sr/(Ca+Sr) molar ratio of Sr-HA coating was 10.1 mol%. Histologic observation showed that new bone appeared on both surfaces after 2 weeks and became mature after 8 weeks. Histomorphometric analysis showed no differences between the two groups in bone-to-implant contact at 2 weeks or in bone area within all threads at 2 and 4 weeks. The Sr-HA coated group had significantly higher bone-to-implant contact at 4 and 8 weeks. Significant differences were also found in bone area at 8 weeks. CONCLUSION: The present study showed that this Sr-HA coating, deposited using an electrochemical process, has the potential to enhance implant osseointegration.

Fabrication, characterization, and biological assessment of multilayer DNA coatings on sandblasted-dual acid etched titanium surface.

As local gene therapy has received attention, immobilizing functional gene onto irregular oral implant surface has become an advanced challenge. Electrostatic layer-by-layer (LBL) assembly technique could achieve this goal and allow local and efficient administration of genes to the target cells. In this study, multilayers of cationic lipid/plasmid DNA (pEGFP-C1) complex (LDc) and anionic hyaluronic acid were assembled onto sandblasted-dual acid etched titanium disks by the LBL technique. Surface characteristics of the coatings were performed by x-ray photospectroscopy (XPS), contact angle measurements, and scanning electron microscopy (SEM). The cell biological characteristics of the coatings were evaluated by in vitro experiments. SEM results demonstrated that the porous titanium surface was gradually flattened with the increase of the multilayer. The XPS survey indicated that the N element was found from the coating. The coating degradation and pEGFP-C1 releasing kinetics showed that the more assembled layer numbers were, the larger the amount of DNA released in the first 30 h. MC3T3-E1 cells were cultured directly on the DNA-loaded surface. Higher enhanced green fluorescent protein (EGFP) expression efficiency was achieved by increasing the number of layers when cells were cultured after 24 or 72 h. The MC3T3-E1 cell viability on the surface of multilayer DNA coatings was significantly higher than that on control porous titanium surface. It was concluded that the approach established by the LBL technique had great potential in immobilizing gene coatings onto the porous titanium surface and subsequently influenced the function of the cultured cell.