In Vitro and In Vivo Antimicrobial Activity of Antibiotic-Conjugated Carriers with Rapid pH-Responsive Release Kinetics.

Two representative antibiotics, cephradine (CP) and moxifloxacin (MX), are covalently conjugated with a ß-cyclodextrin (ß-CD)-based carrier via pH-responsive 1-methyl-2-(2'-carboxyethyl) maleic acid amide (MCM) linkers with excellent conjugation efficiency via simple mixing. At pH 5.5, 90% and 80% of the CP and MX, respectively, are released from the carriers within 30 min, in contrast with the much-delayed release profile at pH 7.4. The in vitro inhibitory effect of ß-CD-MCM-CP on the growth of Staphylococcus aureus is significantly lower than that of free CP at pH 7.4, but it reaches the level of free CP at pH 5.5. Moreover, S. aureus develops significant CP resistance after pretreatment with free CP, whereas the initial CP sensitivity is maintained after pretreatment with ß-CD-MCM-CP at pH 7.4. However, ß-CD-MCM-MX exhibits no such pH-responsive activity against Bacteroides fragilis, probably due to the insufficient stability of the MX conjugation at pH 7.4. In nondiabetic and diabetic mouse models, ß-CD-MCM-CP significantly reduces the subcutaneous abscess scores and the bacterial counts in the abscess, although this represents only a marginal improvement in antimicrobial activity compared to free CP.

A Facial Recognition Mobile App for Patient Safety and Biometric Identification: Design, Development, and Validation.

BACKGROUND: Patient verification by unique identification is an important procedure in health care settings. Risks to patient safety occur throughout health care settings by failure to correctly identify patients, resulting in the incorrect patient, incorrect site procedure, incorrect medication, and other errors. To avoid medical malpractice, radio-frequency identification (RFID), fingerprint scanners, iris scanners, and other technologies have been implemented in care settings. The drawbacks of these technologies include the possibility to lose the RFID bracelet, infection transmission, and impracticality when the patient is unconscious. OBJECTIVE: The purpose of this study was to develop a mobile health app for patient identification to overcome the limitations of current patient identification alternatives. The development of this app is expected to provide an easy-to-use alternative method for patient identification. METHODS: We have developed a facial recognition mobile app for improved patient verification. As an evaluation purpose, a total of 62 pediatric patients, including both outpatient and inpatient, were registered for the facial recognition test and tracked throughout the facilities for patient verification purpose. RESULTS: The app was developed to contain 5 main parts: registration, medical records, examinations, prescriptions, and appointments. Among 62 patients, 30 were outpatients visiting plastic surgery department and 32 were inpatients reserved for surgery. Whether patients were under anesthesia or unconscious, facial recognition verified all patients with 99% accuracy even after a surgery. CONCLUSIONS: It is possible to correctly identify both outpatients and inpatients and also reduce the unnecessary cost of patient verification by using the mobile facial recognition app with great accuracy. Our mobile app can provide valuable aid to patient verification, including when the patient is unconscious, as an alternative identification method.

Hygrobot: A self-locomotive ratcheted actuator powered by environmental humidity.

Microrobots that are light and agile yet require no artificial power input can be widely used in medical, military, and industrial applications. As an actuation system to drive such robots, here we report a biologically inspired bilayer structure that harnesses the environmental humidity energy, with ratchets to rectify the motion. We named this actuator-ratchet system the hygrobot. The actuator uses a hygroscopically responsive film consisting of aligned nanofibers produced by directional electrospinning, which quickly swells and shrinks in lengthwise direction in response to the change of humidity. The ratchets based on asymmetric friction coefficients rectify oscillatory bending motion in a directional locomotion. We mathematically analyzed the mechanical response of the hygrobot, which allowed not only prediction of its performance but also the optimal design to maximize the locomotion speed given geometric and environmental constraints. The hygrobot sterilized a trail across an agar plate without any artificial energy supply.

Effect of silver addition on the properties of nickel-titanium alloys for dental application.

Equiatomic and near-equiatomic nickel-titanium alloys exhibit a shape-memory effect and superelasticity. However, the properties of such alloys are extremely sensitive to the precise nickel-titanium ratio and the addition of alloying elements. High corrosion resistance is necessary for biomedical applications, especially orthodontic. The purpose of this study was to investigate the effect of silver addition to nickel-titanium alloys for dental and medical application. Arc melting, homogenization, hot rolling, and solution heat treatment were performed to prepare the nickel-titanium-silver (NiTi-Ag) specimens. The properties of the ternary NiTi-Ag alloys such as phase-transformation temperature, microstructure, microhardness, corrosion resistance, and cytotoxicity were investigated. The NiTi-Ag alloys showed low silver recovery rate for the cast alloy, due to silver's low evaporation temperature, and low silver solubility in nickel-titanium. Silver addition to nickel-titanium increased the transition temperature range to 100 degrees C and stabilized the martensitic phase (monoclinic structure) at room temperature, because the martensitic transformation starting temperature (Ms) was above room temperature. Martensitic and austenitic phases existed in X-ray diffraction patterns of solution-annealed NiTi-Ag alloys. The silver addition was considered to improve the corrosion resistance and form a stable passive film. Significantly, the mechanical properties of the silver-added alloys were dependent upon the amount of alloying addition. There was no toxicity in the NiTi-Ag alloys, as the response index showed none or mild levels.

Ablation of STAT3 in the B Cell Compartment Restricts Gammaherpesvirus Latency In Vivo.

UNLABELLED: A challenging property of gammaherpesviruses is their ability to establish lifelong persistence. The establishment of latency in B cells is thought to involve active virus engagement of host signaling pathways. Pathogenic effects of these viruses during latency or following reactivation can be devastating to the host. Many cancers, including those associated with members of the gammaherpesvirus family, Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus, express elevated levels of active host signal transducer and activator of transcription-3 (STAT3). STAT3 is activated by tyrosine phosphorylation in response to many cytokines and can orchestrate effector responses that include proliferation, inflammation, metastasis, and developmental programming. However, the contribution of STAT3 to gammaherpesvirus pathogenesis remains to be completely understood. This is the first study to have identified STAT3 as a critical host determinant of the ability of gammaherpesvirus to establish long-term latency in an animal model of disease. Following an acute infection, murine gammaherpesvirus 68 (MHV68) established latency in resident B cells, but establishment of latency was dramatically reduced in animals with a B cell-specific STAT3 deletion. The lack of STAT3 in B cells did not impair germinal center responses for immunoglobulin (Ig) class switching in the spleen and did not reduce either total or virus-specific IgG titers. Although ablation of STAT3 in B cells did not have a global effect on these assays of B cell function, it had long-term consequences for the viral load of the host, since virus latency was reduced at 6 to 8 weeks postinfection. Our findings establish host STAT3 as a mediator of gammaherpesvirus persistence. IMPORTANCE: The insidious ability of gammaherpesviruses to establish latent infections can have detrimental consequences for the host. Identification of host factors that promote viral latency is essential for understanding latency mechanisms and for therapeutic interventions. We provide the first evidence that STAT3 expression is needed for murine gammaherpesvirus 68 to establish latency in primary B cells during an active immune response to infection. STAT3 deletion in B cells does not impair adaptive immune control of the virus, but loss of STAT3 in B cells has a long-lasting impact on viral persistence. These results indicate a potential therapeutic benefit of STAT3 inhibitors for combating gammaherpesvirus latency and, thereby, associated pathologies.