Micro-/Nano-Scales Direct Cell Behavior on Biomaterial Surfaces.

Cells are the smallest living units of a human body's structure and function, and their behaviors should not be ignored in human physiological and pathological metabolic activities. Each cell has a different scale, and presents distinct responses to specific scales: Vascular endothelial cells may obtain a normal function when regulated by the 25 µm strips, but de-function if the scale is removed; stem cells can rapidly proliferate on the 30 nm scales nanotubes surface, but stop proliferating when the scale is changed to 100 nm. Therefore, micro and nano scales play a crucial role in directing cell behaviors on biomaterials surface. In recent years, a series of biomaterials surface with micro and/or nano scales, such as micro-patterns, nanotubes and nanoparticles, have been developed to control the target cell behavior, and further enhance the surface biocompatibility. This contribution will introduce the related research, and review the advances in the micro/nano scales for biomaterials surface functionalization.

Preparative separation of crocins and geniposide simultaneously from gardenia fruits using macroporous resin and reversed-phase chromatography.

Gardenia fruits contain valuable natural food colorants including crocins (gardenia yellow) and geniposide. In this study, a process for the enrichment of crocins and geniposide simultaneously from gardenia fruits was developed using macroporous resin and RP chromatography. The performance of eight different types of macroporous resins was evaluated. Static absorption/desorption experiments revealed that LX60 possessed optimal separating capacity. Further dynamic absorption/desorption experiments on LX60 columns were conducted to obtain the optimal parameters. After one run treatment with LX60, the content of crocin-1 in gardenia yellow reached 29.6%, while geniposide in another fraction reached 83.4%. An extract of crocins was obtained from gardenia yellow in a second-stage separation using RP medium-pressure LC, with its color value to be 756 and the content of crocin-1 reaching 60.8%. The separation process was highly efficient, low cost, and compact, which may be informative for purifications of other natural products from complex plant extracts.

Bond strength of metal-free polyether-ether-ketone knee prostheses compared to metal knee prostheses with bone cement: A preliminary in vitro study.

BACKGROUND: Total knee arthroplasty is the most effective treatment for advanced-stage knee arthritis, and the majority of knee prostheses are made of metal. Nevertheless, metal prostheses still have several problems. The objective of this study is to introduce new metal-free knee prostheses made of polyether-ether-ketone (PEEK) and to compare their cement bond strength with metal prostheses. METHODS: Twelve sets of knee prostheses were divided into four groups (unloaded PEEK, unloaded Metal, 10 million cycles (MC) PEEK, 10 MC Metal, N = 3 each), and then attached to composite bones using bone cement. Both the 10 MC PEEK and 10 MC Metal groups were subjected to dynamic gait simulations of 10 MC, whereas the other two sets were not. Afterwards, a pull-off strength test was performed on the femoral prostheses and a shear strength test was performed on the tibial prostheses. RESULTS: No apparent cracks were observed in the bone cement after subjecting the PEEK and Metal groups to 10 million cycles of dynamic simulation. No statistically significant differences were observed (p > .05) in the strength tests for unloaded PEEK vs. unloaded Metal, 10 MC PEEK vs.10 MC Metal in the femoral pull-off test, and for unloaded PEEK vs. unloaded Metal in the tibial shear test. The shear strength of 10 MC PEEK was significantly lower (p < .05) compared to that of 10 MC Metal. CONCLUSIONS: By comparing the force analysis of previous investigations on knee prostheses with the failure pattern observed in the PEEK knee prosthesis of this study, which replicates that of the metal prosthesis. We believe that the combination of the peek knee prosthesis with bone cement is reliable. We anticipate that metal-free PEEK knee prostheses will find application in Total Knee Arthroplasty (TKA) in the future, thereby benefiting patients.

Stem cells immortalized by hTERT perform differently from those immortalized by SV40LT in proliferation, differentiation, and reconstruction of matrix microenvironment.

Although matrix microenvironment has the potential to improve expanded stem cell proliferation and differentiation capacity, decellularized extracellular matrix (dECM) deposited by senescent cells does not contribute to the rejuvenation of adult stem cells, which has become a barrier to personalized stem cell therapy. Genetic modification is an effective strategy to protect cells from senescence but it carries the increased risk of malignant transformation and genetic instability. In this study, lentivirus carrying either human telomerase reverse transcriptase (hTERT) or simian virus 40 large T antigen (SV40LT) was used to transduce human infrapatellar fat pad-derived stem cells (IPFSCs). We found that virus transduction modified the proliferative, chondrogenic, and adipogenic abilities of IPFSCs. Interestingly, dECM deposited by immortalized cells significantly influenced replicative senescent IPFSCs in proliferation and differentiation preference, the effect of which is hinged on the approach of immortalization using either SV40LT or hTERT. Our findings indicate both dECM expansion and immortalization strategies can be used for replicative senescent adult stem cells' proliferation and lineage-specific differentiation, which benefits future stem cell-based tissue regeneration. This approach may also work for adult stem cells with premature senescence in elderly/aged patients, which needs further investigation. STATEMENT OF SIGNIFICANCE: Adult stem cells are a promising solution for autologous cell-based therapy. Unfortunately, cell senescence due to donor age and/or ex vivo expansion prevents clinical application. Recent progress with decellularized extracellular matrix provides a potential for the rejuvenation of senescent stem cells by improving their proliferation and differentiation capacities. Given the fact that the young matrix can provide a healthy and energetic microenvironment, in this study, two approaches using lentivirus transduction of hTERT and SV40LT were compared. The goal was to immortalize donor cells for deposition of decellularized extracellular matrix. The matrix was demonstrated to contribute diverging effects on the chondrogenic and adipogenic differentiation of expanded stem cells and exhibited proliferation benefits as well. These findings provide an invaluable asset for stem cell-based tissue regeneration.

Treatment of traumatic intracranial aneurysm: Experiences at a single center.

OBJECTIVE: To report the treatment and outcome of traumatic intracranial aneurysm (TICA) cases at the Southwest Hospital, Army Medical University in China. PATIENTS AND METHODS: All patients diagnosed with TICA at our institution from January 1, 1977, to October 31, 2018, and meeting the inclusion/exclusion criteria were included in the study. Cases were reported separately for those diagnosed before 1998 and those after 1998. RESULTS: A total of 25 patients were included in the study. Ten were diagnosed with TICA prior to 1998. Seven of these 10 patients were treated surgically with parent artery sacrificed, including aneurysmectomy, trapping, and bypass. The mean Glasgow Outcome Scale (GOS) score for the 7 patients with surgical treatment was 3.1. Three of the 10 patients died of severe complications, including intracranial infection, delayed bleeding, and deadly injury. After 1998, 15 patients were diagnosed with TICA. Thirteen presented with head trauma and two with iatrogenic TICA following ventricle drainage or sphenoid ridge meningioma resection. Thirteen were treated with endovascular treatment, including coil alone, glue, coil-associated glue, stent alone, stent-assisted coil embolization, one with clipping, and one with conservative treatment. The 13 patients with endovascular treatment achieved a mean GOS score of 4.5. Among the 13 patients, one died from intracranial infection, one suffered recurrence, and one had intraoperative rupture. CONCLUSION: Although the treatment of TICA has traditionally been surgical, endovascular treatment with different techniques, such as endovascular patch, provides a valuable alternative. Currently, the flow diverter is a popular embolization device and may represent another valid treatment option for TICA.

A Dual-Model Imaging Theragnostic System Based on Mesoporous Silica Nanoparticles for Enhanced Cancer Phototherapy.

Mesoporous silica nanoparticles (MSNs) show great promise to be exploited as versatile multifunctional nanocarriers for effective cancer diagnosis and treatment. In this work, perfluorohexane (PFH)-encapsulated MSNs with indocyanine green (ICG)-polydopamine (PDA) layer and poly(ethylene glycol)-folic acid coating (designated as MSNs-PFH@PDA-ICG-PEG-FA) are successfully fabricated to achieve tumor ultrasonic (US)/near-infrared fluorescence (NIRF) imaging as well as photothermal therapy (PTT)/photodynamic therapy (PDT). MSNs-PFH@PDA-ICG-PEG-FA exhibits good monodispersity with high ICG loading, significantly enhances ICG photostability, and greatly improves cellular uptake. Upon single 808 nm NIR irradiation, the nanocarrier not only efficiently generates hyperthermia to realize PTT, but also produces reactive oxygen species (ROS) for effective PDT. Meanwhile, NIR irradiation can trigger PFH to undergo vaporization and provide a super-resolution US image. Thus, the PTT/PDT combination therapy can be dually guided by PFH-induced US imaging and ICG-induced NIRF imaging. In vivo antitumor studies demonstrate that PTT/PDT from MSNs-PFH@PDA-ICG-PEG-FA significantly inhibits tumor growth and achieves a cure rate of 60% (three out of five mice are completely cured). Hence, the multifunctional MSNs appear to be a promising theragnostic nanoplatform for multimodal cancer imaging and therapy.

Selective determination of dopamine in the presence of high concentration of ascorbic acid using nano-Au self-assembly glassy carbon electrode.

The cysteamine (CA) was bound onto surface of the pretreated glassy carbon electrode (GC) with cyclic voltammetry (CV). Gold nanoparticles were self-assembled to the electrode binding with cysteamine via strong Au-S covalent bond to fabricate the nano-Au self-assembled modified electrode (nano-Au/CA/GC). The modified electrode was characterized with cyclic voltammetric and ac impedance methods. The electrochemical behavior of dopamine (DA) on the modified electrode was investigated with cyclic voltammetry and differential pulse voltammetry (DPV). A well-defined redox peaks of DA on the nano-Au/CA/GC electrode were obtained at E(pa)=0.175 V and E(pc)=0.146 V (vs. SCE), respectively. The peak current of DA is linear with the concentration of DA in the range of 1.0 x 10(-8) mol L(-1) to 2.5 x 10(-5) mol L(-1), with the correlation coefficient of 0.998. The detection limit is 4.0 x 10(-9)mol L(-1) (S/N=3). The modified electrode exhibited an excellent reproducibility, sensibility and stability for determination of DA in the presence of high concentration AA, and can be applied to determinate dopamine injection, with satisfied result.

Adjunct steroids in the treatment of peritonsillar abscess: A systematic review.

OBJECTIVES: This study systematically reviews the existing literature on the efficacy of adjuvant corticosteroids in improving clinical outcomes after peritonsillar abscess (PTA) drainage. STUDY DESIGN: Systematic review. METHODS: We performed a literature search of MEDLINE, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Scopus, Embase, and ClinicalTrials.gov from inception to June 2016. Inclusion criteria included randomized controlled trials (RCTs) evaluating adjuvant corticosteroids after PTA drainage. Data were systematically collected on study design, patient demographics, and clinical characteristics. Two independent investigators reviewed all manuscripts and summarized the data. RESULTS: Three RCTs comprising 153 patients were included. The results were not pooled due to heterogeneity in the method in which outcomes were measured and reported. The trials also varied on the type of steroid (dexamethasone, methylprednisolone) administered and method of drainage (incision, aspiration). All three RCTs reported statistically significant improvement in body temperature from adjuvant steroid administration compared to placebo. Pain scores, mouth opening, time to painless oral intake, and duration of hospitalization were significantly improved in only one or two of the three RCTs between the steroid and control group. No adverse side effects from steroid administration were reported. CONCLUSIONS: Steroids as an adjunct therapy to the treatment of PTA may result in faster recovery. However, further investigation with larger RCTs and standardized outcomes are warranted. LEVEL OF EVIDENCE: 1a. Laryngoscope, 128:72-77, 2018.

Rapid prototyping technology and its application in bone tissue engineering.

Bone defects arising from a variety of reasons cannot be treated effectively without bone tissue reconstruction. Autografts and allografts have been used in clinical application for some time, but they have disadvantages. With the inherent drawback in the precision and reproducibility of conventional scaffold fabrication techniques, the results of bone surgery may not be ideal. This is despite the introduction of bone tissue engineering which provides a powerful approach for bone repair. Rapid prototyping technologies have emerged as an alternative and have been widely used in bone tissue engineering, enhancing bone tissue regeneration in terms of mechanical strength, pore geometry, and bioactive factors, and overcoming some of the disadvantages of conventional technologies. This review focuses on the basic principles and characteristics of various fabrication technologies, such as stereolithography, selective laser sintering, and fused deposition modeling, and reviews the application of rapid prototyping techniques to scaffolds for bone tissue engineering. In the near future, the use of scaffolds for bone tissue engineering prepared by rapid prototyping technology might be an effective therapeutic strategy for bone defects.

Super-Robust Polylactide Barrier Films by Building Densely Oriented Lamellae Incorporated with Ductile in Situ Nanofibrils of Poly(butylene adipate-co-terephthalate).

Remarkable combination of excellent gas barrier performance, high strength, and toughness was realized in polylactide (PLA) composite films by constructing the supernetworks of oriented and pyknotic crystals with the assistance of ductile in situ nanofibrils of poly(butylene adipate-co-terephthalate) (PBAT). On the basis that the permeation of gas molecules through polymer materials with anisotropic structure would be more frustrated, we believe that oriented crystalline textures cooperating with inerratic amorphism can be favorable for the enhancement of gas barrier property. By taking full advantage of intensively elongational flow field, the dispersed phase of PBAT in situ forms into nanofibrils, and simultaneously sufficient row-nuclei for PLA are induced. After appropriate thermal treatment with the acceleration effect of PBAT on PLA crystallization, oriented lamellae of PLA tend to be more perfect in a preferential direction and constitute into a kind of network interconnecting with each other. At the same time, the molecular chains between lamellae tend to be more extended. This unique structure manifests superior ability in ameliorating the performance of PLA film. The oxygen permeability coefficient can be achieved as low as 2 × 10(-15) cm(3) cm cm(-2) s(-1) Pa(-1), combining with the high strength, modulus, and ductility (104.5 MPa, 3484 MPa, and 110.6%, respectively). The methodology proposed in this work presents an industrially scalable processing method to fabricate super-robust PLA barrier films. It would indeed push the usability of biopolymers forward, and certainly prompt wider application of biodegradable polymers in the fields of environmental protection such as food packaging, medical packaging, and biodegradable mulch.

Prevention of abdominal adhesion formation by thermosensitive PECE-hydrogel in a rat uterine horn model.

In this work, we investigated the efficacy of PECE-hydrogel in preventing postsurgical peritoneal adhesions in the rat uterine horn model. Standardized surgical traumas were applied to the peritoneum of the abdominal wall and the uterine horns. PECE hydrogel was applied to the two wound surfaces. Animals were euthanized at different times after surgery, and the gross necropsy findings were documented. Adhesion formation was assessed according to adhesion extent and adhesion severity, and the hydrogel degradation and healing of peritoneal wounds were observed. The remesothelialization was dynamically observed by scanning electron microscope. The results showed that none of the animals in the hydrogel-treated group (n = 12) developed adhesion. In contrast, all untreated animals (n = 12) had adhesions that could only be separated by sharp dissection (p < 0.001). The hydrogel could adhere to the peritoneal wounds and gradually disappear from the wounds within 7-9 days and transformed into viscous fluid being completely absorbed within 12 days. The injured parietal and visceral peritoneum was remesothelialized in about 7 and 9 days, respectively. This work confirmed that PECE hydrogel holds promise as a novel absorbable biomaterial for the reduction of postoperative adhesions after laparotomy.

A L-cysteine sensor based on Pt nanoparticles/poly(o-aminophenol) film on glassy carbon electrode.

Platinum nanoparticles (nano-Pt) and poly(o-aminophenol) (POAP) were fabricated onto the glassy carbon electrode(GCE) to form the nano-Pt/POAP/GCE for the electrochemical determination of L-cysteine. The POAP film was obtained through electrochemical polymerization of o-aminophenol on GCE. The nano-Pt was electrochemically deposited onto the surface of the activated POAP/GCE The resultant nano-Pt/POAP/GCE was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and showed excellent electrochemical response to L-cysteine at low oxidative potential in Britton-Robinson (BR) buffer solution (pH=3.0), with good stability and sensitivity, and featured with a low detection limit (0.08 microM, signal/noise=3) and wide linear range (0.4 microM-6.3mM).The mechanism for the electrochemical oxidation of L-cysteine on the nano-Pt/POAP/GCE was also investigated.

[Preparation and application of gel chip].

A new method for manufacturing three-dimensional gel film-coated chips was described in this paper and its advantages were evaluated by its application. A patch of polyacrylamide gel (15mm x 15mm x 20 microm) was fixed on the glass surface with Bind-Silane treatment, then activated by glutaraldehyde. The aldehyde groups in gel provided reactive sites that allowed covalent immobilization of molecules containing amino groups. Oligonucleotides were mechanically spotted by GMS 417 Arrayer. After hybridization with Cy-3 labeled probes, fluorescence signals of perfect binding can be discriminated from mismatched ones. Compared with two-dimensional glass chip, the capacity of oligonucleotides immobilized on gel film-coated chip is over 100 times. And the gel film-coated chip have lower background and shorter hybridization time. Monoclonal antibodys of cytokine IL-4, IL-5, IL-6, IL-7, ANG, I-309 and VEGF were also immobilized on the gel film-coated chips to make protein microarrays. After incubation with serum of breast cancer patients or normal persons, the microarray reacted with biotin-labeled second antibodys of cytokines and Cy-3-labeled streptavidin sequentially. Results show IL-4, IL-5, I-309 and VEGF of patients have higher expression level than normal persons. This kind of protein microarrays can be potentially helpful to clinical diagnosis. Furthermore different oligonucleotides or proteins can be performed in parallel in a single reaction with minimal amount of binding reagents. Such gel film-coated chips can be used widely in the fabrication of oligonucleotides and proteins microarrays.