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  1. Morsin M, Nafisah S, Sanudin R, Razali NL, Mahmud F, Soon CF
    PLoS One, 2021;16(11):e0259730.
    PMID: 34748606 DOI: 10.1371/journal.pone.0259730
    An anisotropic structure, gold (Au) nanoplates was synthesized using a two-step wet chemical seed mediated growth method (SMGM) directly on the substrate surface. Prior to the synthesis process, poly-l-lysine (PLL) as a cation polymer was used to enhance the yield of grown Au nanoplates. The electrostatic interaction of positive charged by PLL with negative charges from citrate-capped gold nanoseeds contributes to the yield increment. The percentage of PLL was varied from 0% to 10% to study the morphology of Au nanoplates in term of shape, size and surface density. 5% PLL with single layer treatment produce a variety of plate shapes such as hexagonal, flat rod and triangular obtained over the whole substrate surface with the estimated maximum yield up to ca. 48%. The high yield of Au nanoplates exhibit dual plasmonic peaks response that are associated with transverse and longitudinal localized surface plasmon resonance (TSPR and LSPR). Then, the PLL treatment process was repeated twice resulting the increment of Au nanoplates products to ca. 60%. The thin film Au nanoplates was further used as sensing materials in plasmonic sensor for detection of boric acid. The anisotropic Au nanoplates have four sensing parameters being monitored when the medium changes, which are peak position (wavelength shift), intensity of TSPR and LSPR, and the changes on sensing responses. The sensor responses are based on the interaction of light with dielectric properties from surrounding medium. The resonance effect produces by a collection of electron vibration on the Au nanoparticles surface after hit by light are captured as the responses. As a conclusion, it was found that the PLL treatment is capable to promote high yield of Au nanoplates. Moreover, the high yield of the Au nanoplates is an indication as excellent candidate for sensing material in plasmonic sensor.
    Matched MeSH terms: Polylysine*
  2. Alirezalu K, Pirouzi S, Yaghoubi M, Karimi-Dehkordi M, Jafarzadeh S, Mousavi Khaneghah A
    Meat Sci, 2021 Jun;176:108475.
    PMID: 33684807 DOI: 10.1016/j.meatsci.2021.108475
    In the current study, the effect on packaged beef fillets (1 × 5 × 8 cm) of using active chitosan film (1%) was investigated. The fillets were stored at 4 °C for 12 days, and the film contained ɛ-polylysine (ɛ-PL) (0.3, 0.6, and 0.9% w/w). Chemical, microbiological, sensory properties, and quality indices of the fillets were investigated. Added to these factors was an assessment of the influence of ɛ-polylysine incorporation on the optical, structural, barrier, and mechanical specifications (elongation at break and tensile strength) of chitosan films. Based on the findings, a significant difference among the corresponding values to thickness, color, water vapor permeability (WVP), and mechanical specifications between the treated films by ɛ-PL and untreated films were noted. In addition, higher values of thickness and tensile strength were correlated with ɛ-PL added active chitosan films while compared with control samples. Additionally, no significant differences regarding the proximate composition (including protein, moisture, and fat) among beef fillet samples were observed. In this regard, due to significantly lower levels of pH, TVB-N, and TBARS ɛ-PL in enriched films, this technique demonstrated some protective effects on beef fillets. Another observation was that lower levels of the total viable count, coliform, mold, yeasts, and higher sensory properties were significantly associated with samples with added ɛ-PL (0.9%). Therefore, adding ɛ-PL into chitosan films could be introduced as an effective technique to extend the shelf life of beef fillets and maintain their quality indices during refrigerated storage.
    Matched MeSH terms: Polylysine/chemistry
  3. Chong PN, Sangu M, Huat TJ, Reza F, Begum T, Yusoff AAM, et al.
    Malays J Med Sci, 2018 Nov;25(6):28-45.
    PMID: 30914877 MyJurnal DOI: 10.21315/mjms2018.25.6.4
    Background: Following brain injury, development of hippocampal sclerosis often led to the temporal lobe epilepsy which is sometimes resistant to common anti-epileptic drugs. Cellular and molecular changes underlying epileptogenesis in animal models were studied, however, the underlying mechanisms of kainic acid (KA) mediated neuronal damage in rat hippocampal neuron cell culture alone has not been elucidated yet.

    Methods: Embryonic day 18 (E-18) rat hippocampus neurons were cultured with poly-L-lysine coated glass coverslips. Following optimisation, KA (0.5 μM), a chemoconvulsant agent, was administered at three different time-points (30, 60 and 90 min) to induce seizure in rat hippocampal neuronal cell culture. We examined cell viability, neurite outgrowth density and immunoreactivity of the hippocampus neuron culture by measuring brain derived neurotrophic factor (BDNF), γ-amino butyric acid A (GABAA) subunit α-1 (GABRA1), tyrosine receptor kinase B (TrkB), and inositol trisphosphate receptor (IP3R/IP3) levels.

    Results: The results revealed significantly decreased and increased immunoreactivity changes in TrkB (a BDNF receptor) and IP3R, respectively, at 60 min time point.

    Conclusion: The current findings suggest that TrkB and IP3 could have a neuroprotective role which could be a potential pharmacological target for anti-epilepsy drugs.

    Matched MeSH terms: Polylysine
  4. Lee KH, Lee PM, Siaw YS
    J Chem Technol Biotechnol, 1993;57(1):27-32.
    PMID: 7763683
    Aminoacylase I (EC 3.5.1.14) encapsulated in calcium alginate beads stabilized with poly-L-lysine was used for the production of L-phenylalanine by the hydrolysis of a racemic mixture of N-acetyl-DL-phenylalanine. The immobilized aminoacylase was studied with respect to operational stability, thermal stability, effects of pH and temperature and kinetic constants. The leakage of enzyme from the stabilized beads was eliminated. The immobilized enzyme retained high biological activity. The Km and Vmax values for the stabilized beads were 11.11 mmol dm-3 and 0.076 mumol min-1 respectively. The optimum pH and temperature for the hydrolysis were 6.5 and 55 degrees C respectively. Scanning electron micrographs revealed crosslinked structures on the surface of the beads. The operational performances of the beads in a batch reaction and a packed-bed bioreactor for continuous reaction were investigated. With batch reaction, only about 5% of enzyme activity was lost within ten reaction cycles and there was no significant loss of activity over 600 h of continuous operation after equilibrium was reached, and a conversion yield of about 80% was obtained.
    Matched MeSH terms: Polylysine
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