A novel acid-responsive polymer coating with antibacterial and antifouling properties for the prevention of biofilm-associated infections.

Chronic infections caused by the pathogenic biofilms on implantable medical devices pose an increasing challenge. To combat long-term biofilm-associated infections, we developed a novel dual-functional polymer coating with antibacterial and antifouling properties. The coating consists of N-vinylpyrrolidone (NVP) and 3-(acrylamido)phenylboronic acid (APBA) copolymer brushes, which bind to curcumin (Cur) as antibacterial molecules through acid-responsive boronate ester bonds. In this surface design, the hydrophilic poly (N-vinylpyrrolidone) (PVP) component improved antifouling performance and effectively prevented bacterial adhesion and aggregation during the initial phases. The poly (3-(acrylamido) phenylboronic acid) (PAPBA, abbreviated PB) component provided binding sites for Cur by forming acid-responsive boronate ester bonds. When fewer bacteria overcame the anti-adhesion barrier and colonized, the surface responded to the decreased microenvironmental pH by breaking the boronate ester bonds and releasing curcumin. This responsive mechanism enabled Cur to interfere with biofilm formation and provide a multilayer anti-biofilm protection system. The coating showed excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, preventing biofilm formation for up to 7 days. The coating also inhibited protein adsorption and platelet adhesion significantly. This coating also exhibited high biocompatibility with animal erythrocytes and pre-osteoblasts. This research offers a promising approach for developing novel smart anti-biofilm coating materials.

An approach of pectin from Citrus aurantium L. for superabsorbent resin with superior quality for hygiene products: Salt resistance, antibacterial, nonirritant and biodegradability.

In this paper, a kind of superabsorbent resin (SAR) with superior quality for hygiene products was developed using Fructus Aurantii Immaturus pectin (FAIP) from Citrus aurantium L.. FAIP-g-AM/AMPS SAR was established by free radical graft co-polymerization with FAIP as skeleton structure, N, N'-Methylene-bis (acrylamide) (MBA) as the cross-linker. Meanwhile, the functional monomers of acrylamide (AM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) were introduced. The structure and morphology of FAIP-g-AM/AMPS were characterized by FTIR, 13C NMR, XRD, SEM and TG-DSC analysis. The results confirmed that the AFIP-g-AM/AMPS SAR was successfully prepared, which exhibited a three-dimensional (3D) network structure and an excellent thermal stability. The absorption and retention capacity of FAIP-g-AM/AMPS was comparable to or even better than commercial diapers and sanitary napkins. Significantly, FAIP-g-AM/AMPS itself exhibited excellent antibacterial and safety. FAIP-g-AM/AMPS has an inhibition ratio of 97.1 % for Escherichia coli (E. coli) and 98.5 % for Staphylococcus aureus (S. aureus), and was non-irritating and non-allergic to the skin. In addition, FAIP-g-AM/AMPS presented amazing biodegradability and a weight loss reached 37.1 % after 30 days by soil burial test. The research provides a safe and high-performance SAR, which expected to be used in hygiene products such as baby diapers, adult incontinence pads and sanitary napkins.

Theoretical study on the radical scavenging activity and mechanism of four kinds of Gnetin molecule.

As an important subgroup of resveratrol oligomers, Gnetins received much attention due to their antioxidants. The four Gnetin molecules are divided into two major categories according to different structures, type-A (Gnetin-C, Gnetin-D) and type-B (Gnetin-L, Gnetin-F). Density functional theory (DFT) has been performed thermodynamically and kinetically in detail to analyze the structure and antioxidant activity of four Gnetins toward OH/OOH radical in the gas and solvents phase with four possible antioxidant mechanisms, namely, Hydrogen-atom transfer (HAT), Single electron transfer followed by proton transfer (SET-PT), Sequential proton-loss electron transfer (SPLET), and Radical adduct formation (RAF). From these calculations; Gnetins' order of antioxidant activity was estimated as: Gnetin-C ≈ Gnetin-L > Resveratrol > Gnetin-D > Gnetin-F. All investigations suggested that type A has a higher radical scavenging activity compared to type B. On the basis of the structure-activity relationship, type A structure may have more vital antioxidant potential in the future.

Simultaneous Determination of Six Isoflavones from Puerariae Lobatae Radix by CPE-HPLC and Effect of Puerarin on Tyrosinase Activity.

Tyrosinase inhibitors with excellent inhibitory activities and lower side effects have promising applications in the fields of medicine, agriculture, food sciences and cosmetics. In this study, a method for simultaneous separation and determination of six target compounds (puerarin, daidzin, genistein, daidzein, genistin, and formononetin) in Puerariae Lobatae Radix was established by cloud point extraction (CPE) and concentration combined with high performance liquid chromatography (HPLC). To achieve high extraction yields, an ultrasound-assisted extraction method was developed based on a salt-modified Triton X-100 system. The optimal extraction conditions are: surfactant Triton X-100 concentration 0.07 g/mL, liquid-solid ratio 80:1 (mL/g), NaCl addition amount 0.6 g, equilibrium time 40 min, equilibrium temperature 70 °C. Under the optimal conditions, the total maximum extraction yield of the six target isoflavones reached 8.92 mg/g. Using l-tyrosine and l-dopa as substrates, the effects of puerarin on the monophenolase and diphenolase activity of tyrosinase activity were investigated by the enzyme kinetics method. The results showed that puerarin inhibited monophenolase activity with an IC50 of 0.537 mg/mL and activated diphenolase activity. The inhibition type of puerarin on monophenolase and the activation type of puerarin on diphenolase were analyzed by Lineweaver-Burk plots which show that puerarin showed mixed inhibition on monophenolase and mixed activation on diphenolase. Therefore, puerarin can be used as both a tyrosinase inhibitor and a tyrosinase activator.

Caregiving and Its Resulting Effects-The Care Study to Evaluate the Effects of Caregiving on Caregivers of Patients with Advanced Cancer in Singapore.

Informal caregivers (IC) are key to enabling home deaths, where preferred, at the end-of-life. Significant morbidity from advanced cancer can make caregiving burdensome. However, knowledge about the nature of the caregiving burden for caregivers in Singapore is limited. Hence, the key objective in this study was to examine the impact of the caregiving burden on quality of life (QOL), mental health and work capacity among local ICs. Eligible English-speaking ICs of hospitalized advanced cancer patients were recruited through non-random sampling. The Zarit Burden Interview (ZBI), Caregiver Quality of Life Index-Cancer (CQOLC), Center for Epidemiologic Studies Depression Scale-Revised (CESD-R), and Work Productivity and Activity Impairment Questionnaire (WPAI) were interviewer-administered to eligible ICs. Altogether, 16 ICs were surveyed. The mean age of ICs was 43.8 years. Most were children of patients (43.8%), and eight ICs had high burden (ZBI > 17). Those with ZBI > 17 had lower QOL, higher depression scores as well as greater work and activity impairment. In conclusion, high caregiver burden has adverse effects on QOL, mental health and work productivity. Non-physical elements of caregiving (particularly financial and decision-making) and increased number of care roles undertaken by a single IC contribute to high burden. Future interventions for caregiving burden in Singapore should also address the financial and decision-making aspects of caregiving. Outsourcing selected aspects of the caregiving role to community services may reduce the number of caregiving aspects undertaken by a single IC and caregiver burden.

Facilitating terminal discharge: fulfilling the hospitalised patient's wish for home death in the final hours.

BACKGROUND: Terminal discharge (TD) is the rapid discharge of a hospitalised patient when death is imminent. Its time-limited nature makes it challenging, particularly for ward nurses. AIM: To report the development of a structured TD framework, and determine if the framework can expedite TD processes and improve nurses' experience in conducting TDs. METHODS: A 3-phase audit was carried out in a Singapore hospital. The baseline and post intervention audits evaluated the time taken for TD, incidence of prescription errors, continuity of care, and timeliness of equipment arrangement. Nurse satisfaction was assessed through a written survey. Interventions encompassed the implementation of workflow changes and a TD guide. RESULTS: The mean time taken to complete TDs was shorter in the post-compared to pre-intervention phase (2.9±1.4 vs. 4.6±2.3 hours respectively, p<0.01). Approximately 89% of nurses who used the TD guide were satisfied that it made TDs easier. CONCLUSION: A structured TD framework is effective in expediting TDs and improving nurse satisfaction.

What do renal health-care professionals in Singapore think of advance care planning for patients with end-stage renal disease?

AIM: Previous studies have focused either on advance medical directives rather than advance care planning (ACP), or on patient's perspectives on ACP rather than those of the health-care providers. This study aimed to explore the knowledge, attitudes and experience of renal health-care professionals in Singapore on ACP for patients with end-stage renal failure. METHODS: A 41-item questionnaire was distributed to physicians, nurses, medical social workers (MSW) and other allied health professionals working in renal units. The questionnaire had four sections: demographics of the respondents, knowledge of, attitudes to and experience with ACP. RESULTS: Of a total of 620 survey forms, 562 were returned, giving a response rate of 90.6%. Medical social workers and physicians had higher knowledge scores than the rest. Of doctors and MSW, 82.4% and 100%, respectively, considered ACP discussions as part of their role, but only 37.1% of nurses and 38.1% of other allied health-care professionals thought likewise. Nurses appeared to be the least confident in conducting ACP discussions, and most fearful of upsetting patients and families. Medical social workers were the most confident. The main barriers for physicians appeared to be lack of time, concerns regarding family backlash and the perception that patients were not prepared to discuss ACP. CONCLUSION: Training of renal health-care professionals in ACP should aim to correct misunderstandings surrounding ACP, address potential barriers and impart communication skills. In particular, renal nurses will need encouragement to initiate discussions and be equipped with the skills to do so.

[Observation on the protective effect of preventive acupuncture and moxibustion on uterus in ovariectomized rats].

OBJECTIVE: To observe the effect of preventive acupuncture and moxibustion of "Guanyuan" (CV 4) on uterus in ovariectomized (OVX) rats. METHODS: A total of 80 female SD rats were randomly divided into 5 groups: normal control, sham-operation (sham), model, preventive acupuncture (PA) and preventive moxibustion (PM) groups, with 16 cases in each. PA (with the needle retained for 20 min after insertion) and PM (one moxa-cone/rat) were applied to "Guanyuan" (CV 4) separately before ovariectomy, two times a week, 4 weeks altogether. Then, ovariectomy was performed on rats of model, PA and PM groups. Uterus tissue was taken under anesthesia for homogenate (10 rats/group) or sectioning (5-6 microm, 6 rats/group). Uterus estradiol (E2), progestone (P) were detected with radioimmunoassay; superoxide dismutase (SOD), nitric oxide synthase (NOS), and malondialdehyde (MDA) were assayed with immunoturdidimetry. Partial uterus slices were stained with H & E method for observing morphological changes, or stained with immunohistochemical method or with in situ hybridization method for displaying estrogen receptor (ER)-alpha and ER-alpha mRNA expression separately. RESULTS: After ovariectomy, the rat's uterus presented obvious squamous metaplasia, hyperplasy, and thickening of the endomembrane, decrease in glands and blood vessels and increase in fibrous connective tissue, etc; while the situation was evidently better in PA and PM groups. In comparison with normal control group, E2, P contents and SOD, NOS activities of uterus tissue in model group decreased significantly (P < 0.01), while MDA in model group increased evidently (P < 0.01). Compared with model group, uterus P content in PA and PM groups increased obviously (P < 0.05), while uterus MDA decreased apparently (P < 0.01). Compared with normal control group, the expression of ER-alpha and ER-alpha mRNA in model group was downregulated markedly (P < 0.01); after PA and PM, both ER-alpha and ER-alpha mRNA expression increased obviously (P < 0.01). No significant differences were found between PA and PM groups in the above mentioned 7 indexes (P > 0.05). CONCLUSION: Preventive acupuncture and moxibustion of CV4 can postpone the structural degeneration of uterus in OVX rats, which may be related to their effects in modulating the secretion of uterus E2 and P, upregulating the expression of ER-a and ER-alpha mRNA, and improving the anti-oxidative ability.

[Experimental study on changes of expressions of ER-alpha and ER-alpha mRNA in different hypothalamic nuclei and the effect of "preventive acupuncture and moxibustion" in ovariectomy rats].

OBJECTIVE: To explore the mechanism of "preventive acupuncture and moxibustion" for regulating hypothalamic function in ovariectomy rats. METHODS: Thirty female SD rats, aged 3.5 months, were randomly divided into normal group, sham operation group, ovariectomy model group, preventive acupuncture group and preventive moxibustion group. After "preventive acupuncture and moxibustion" were previously given to the preventive acupuncture group and the preventive moxibustion group for one month, respectively. At the same time, ovarietomy was made in the preventive acupuncture group, the preventive moxibustion group and the ovariectomy model group. For the sham operation group, only a little fat around the ovary was removed without ovariectomy, and nothing was not applied to the normal group. Immunohistochemical and in situs hybridization methods were used to investigate changes of expressions of ER-alpha and ER-alpha mRNA in paraventricular nucleus, supraoptic nucleus and arcuate nucleus. RESULTS: In the model group the expressions of ER-alpha and ER-alpha mRNA in paraventricular nucleus and the expression of ER-alpha mRNA in supraoptic nucleus increased significantly (P<0.01), but the expression of ER-alpha dropped significantly in both supraoptic nucleus and arcuate nucleus (P<0.01). After preconditioning with acupuncture or moxibustion, the expression of ER-alpha mRNA in paraventricular nucleus significantly reduced (P<0.05), and the expression of ER-alpha had no significant change (P>0.05); the expression of ER-alpha in supraoptic nucleus and arcuate nucleus significantly increased (P<0.01 or P<0.05), and the expression of ER-alpha mRNA in paraventricular nucleus had no significant change (P>0.05). CONCLUSION: "Preventive acupuncture and moxibustion" at "Guanyuan" (CV 4) have an effect on the expressions of ER-alpha and ER-alpha mRNA in different hypothalamic nuclei in ovariectomy rats, which possibly is one of the ways for modulating the hypothalamic activity.

Protein-free fed-batch culture of non-GS NS0 cell lines for production of recombinant antibodies.

Presented is a novel antibody production platform based on the fed-batch culture of recombinant, NS0-derived cell lines. A standardized fed-batch cell culture process was developed for five non-GS NS0 cell lines using enriched and optimized protein-free, cholesterol-free, and chemically defined basal and feed media. The process performed reproducibly and scaled faithfully from the 2-L to the 100-L bioreactor scale achieving a volumetric productivity of > 120 mg/L per day. Fed-batch cultures for all five cell lines exhibited significant lactate consumption when the cells entered the stationary or death phase. Peak and final lactate concentrations were low relative to a previously developed fed-batch process (FBP). Such low lactate production and high lactate consumption rates were unanticipated considering the fed-batch culture basal medium has an unconventionally high initial glucose concentration of 15 g/L, and an overall glucose consumption in excess of 17 g/L. The potential of this process platform was further demonstrated through additional media optimization, which has resulted in a final antibody concentration of 2.64 +/- 0.19 g/L and volumetric productivity of > 200 mg/L per day in a 13-day FBP for one of the five production cell lines. Use of this standardized protein-free, cholesterol-free NS0 FBP platform enables consistency in development time and cost effectiveness for manufacturing of therapeutic antibodies.