11 research outputs found
Predictors of postoperative delirium among patients undergoing total knee arthroplasty: a literature review
Delirium is a neurocognitive disorder characterized by the presence of disturbance in attention that develops over a short period of time, which is not explained by another preexisting neurocognitive disorder and it is the physiological consequence of another medical condition. Although there are no known causes of delirium, multiple factors are thought to play a role in the development of the disorder. Postoperative delirium is common in hospitalized patients undergoing surgery. Studies have indicated that postoperative delirium incidence varies depending on the type of surgery performed, the criteria used to diagnose delirium, and the population that is being studied. Consequences of postoperative delirium include prolonged hospitalization, decline in cognitive function, and an increase in mortality rate. The purpose of the study was to review the literature on the risk factors of delirium incidence postoperatively among patients undergoing total knee arthroplasty. A literature review on postoperative delirium in total knee arthroplasty patients and its risk factors was conducted using the PubMed database from January 2011 to March 2018, yielding 15 articles that met inclusion criteria. Articles were reviewed for patient demographic characteristics, postoperative delirium diagnosis methods, findings, strengths, and limitations. There was little consistency on the diagnostic measures of postoperative delirium, where nine of the studies used the same standardized tool, but there was still variation in the frequency of the use of the tool. Among patients undergoing total knee arthroplasty (age range: 60 to >80 years), postoperative delirium incidence ranged from 0.6% to 62.5%. Incidence of postoperative delirium was determined by the following risk factors: older age and/or history of psychiatric disorders and/or ethnicity, electrolyte disorders, preoperative cerebrospinal fluid β-amyloid/tau ratio, preexisting obstructive sleep apnea, use of preventative screening measures, vigorous physiotherapy, and type of pain medication prescribed. In conclusion, accurate prediction of risk factors associated with postoperative delirium incidence may help patients, providers, payers, and health systems with decision-making and opportunities for intervention(s) early in the disease course, therefore prioritizing the public health implications associated with postoperative delirium
Enhanced Uptake of Luminescent Quantum Dots by Live Cells Mediated by a Membrane-Active Peptide
The
steady progress made over the past three decades in growing
a variety of inorganic nanomaterials, with discreet control over their
size and photophysical properties, has been exploited to develop several
imaging and sensing applications. However, full integration of these
materials into biology has been hampered by the complexity of delivering
them into cells. In this report, we demonstrate the effectiveness
of a chemically synthesized anticancer peptide to facilitate the rapid
delivery of luminescent quantum dots (QDs) into live cells. We combine
fluorescence imaging microscopy, flow cytometry, and specific endocytosis
inhibition experiments to probe QD–peptide conjugate uptake
by different cell lines. We consistently find that a sizable fraction
of the internalized conjugates does not co-localize with endosomes
or the nuclei. These findings are extremely promising for the potential
integration of various nanomaterials into biological systems
A Multifunctional Polymer Combining the Imidazole and Zwitterion Motifs as a Biocompatible Compact Coating for Quantum Dots
We
introduce a set of multicoordinating imidazole- and zwitterion-based
ligands suited for surface functionalization of quantum dots (QDs).
The polymeric ligands are built using a one-step nucleophilic addition
reaction between polyÂ(isobutylene-<i>alt</i>-maleic anhydride)
and distinct amine-containing functionalities. This has allowed us
to introduce several imidazole anchoring groups along the polymer
chain for tight coordination to the QD surface and a controllable
number of zwitterion moieties for water solubilization. It has also
permitted the introduction of reactive and biomolecular groups for
further conjugation and targeting. The QDs capped with these new ligands
exhibit excellent long-term colloidal stability over a broad range
of pH, toward excess electrolyte, in cell-growth media, and in the
presence of natural reducing agents such as glutathione. These QDs
are also resistant to the oxidizing agent H<sub>2</sub>O<sub>2</sub>. More importantly, by the use of zwitterion moieties as the hydrophilic
block, this polymer design provides QDs with a thin coating and compact
overall dimensions. These QDs are easily self-assembled with full
size proteins expressed with a polyhistidine tag via metal–histidine
coordination. Additionally, the incorporation of amine groups allows
covalent coupling of the QDs to the neurotransmitter dopamine. This
yields redox-active QD platforms that can be used to track pH changes
and detect Fe ions and cysteine through charge-transfer interactions.
Finally, we found that QDs cap-exchanged with folic acid-functionalized
ligands could effectively target cancer cells, where folate-receptor-mediated
endocytosis of QDs into living cells was time- and concentration-dependent
The dual–function of lipoic acid groups as surface anchors and sulfhydryl reactive sites on polymer–stabilized QDs and Au nanocolloids
Nanoparticle-assisted, image-guided laser interstitialthermal therapy for cancer treatment
Laser interstitial thermal therapy (LITT) guided by magnetic resonance imaging (MRI) is a new treatment option for patients with brain and non-central nervous system (non-CNS) tumors. MRI guidance allows for precise placement of optical fiber in the tumor, while MR thermometry provides real-time monitoring and assessment of thermal doses during the procedure. Despite promising clinical results, LITT complications relating to brain tumor procedures, such as hemorrhage, edema, seizures, and thermal injury to nearby healthy tissues, remain a significant concern. To address these complications, nanoparticles offer unique prospects for precise interstitial hyperthermia applications that increase heat transport within the tumor while reducing thermal impacts on neighboring healthy tissues. Furthermore, nanoparticles permit the co-delivery of therapeutic compounds that not only synergize with LITT, but can also improve overall effectiveness and safety. In addition, efficient heat-generating nanoparticles with unique optical properties can enhance LITT treatments through improved real-time imaging and thermal sensing. This review will focus on (1) types of inorganic and organic nanoparticles for LITT; (2) in vitro, in silico, and ex vivo studies that investigate nanoparticles' effect on light–tissue interactions; and (3) the role of nanoparticle formulations in advancing clinically relevant image-guided technologies for LITT.https://doi.org/10.1002/wnan.182
Margatoxin-conjugated quantum dots as a tool for targeted inhibition of the voltage-gated potassium channel Kv1.3 in the olfactory bulb
Development and application of a peptide inhibitor-bound quantum dot targeting the voltage-gated potassium channel Kv1.3 in the olfactory bulb
Intracellular Delivery of Luminescent Quantum Dots Mediated by a Virus-Derived Lytic Peptide
We
describe a new quantum dot (QD)-conjugate prepared with a lytic
peptide, derived from a nonenveloped virus capsid protein, capable
of bypassing the endocytotic pathways and delivering large amounts
of QDs to living cells. The polypeptide, derived from the Nudaurelia capensis Omega virus, was fused onto the
C-terminus of maltose binding protein that contained a hexa-HIS tag
at its N-terminus, allowing spontaneous self-assembly of controlled
numbers of the fusion protein per QD via metal–HIS interactions.
We found that the efficacy of uptake by several mammalian cell lines
was substantial even for small concentrations (10–100 nM).
Upon internalization the QDs were primarily distributed outside the
endosomes/lysosomes. Moreover, when cells were incubated with the
conjugates at 4 °C, or in the presence of chemical endocytic
inhibitors, significant intracellular uptake continued to occur. These
findings indicate an entry mechanism that does not involve endocytosis,
but rather the perforation of the cell membrane by the lytic peptide
on the QD surfaces
Development and Application of a Peptide Inhibitor-Bound Quantum Dot Targeting the Voltage-Gated Potassium Channel KV1.3 in the Olfactory Bulb
Photoligation of an Amphiphilic Polymer with Mixed Coordination Provides Compact and Reactive Quantum Dots
We introduce a new
set of multicoordinating polymers as ligands
that combine two distinct metal-chelating groups, lipoic acid and
imidazole, for the surface functionalization of QDs. These ligands
combine the benefits of thiol and imidazole coordination to reduce
issues of thiol oxidation and weak binding affinity of imidazole.
The ligand design relies on the introduction of controllable numbers
of lipoic acid and histamine anchors, along with hydrophilic moieties
and reactive functionalities, onto a polyÂ(isobutylene-<i>alt</i>-maleic anhydride) chain via a one-step nucleophilic addition reaction.
We further demonstrate that this design is fully compatible with a
novel and mild photoligation strategy to promote the in situ ligand
exchange and phase transfer of hydrophobic QDs to aqueous media under
borohydride-free conditions. Ligation with these polymers provides
highly fluorescent QDs that exhibit great long-term colloidal stability
over a wide range of conditions, including a broad pH range (3–13),
storage at nanomolar concentration, under ambient conditions, in 100%
growth media, and in the presence of competing agents with strong
reducing property. We further show that incorporating reactive groups
in the ligands permits covalent conjugation of fluorescent dye and
redox-active dopamine to the QDs, producing fluorescent platforms
where emission is controlled/tuned by Förster Resonance Energy
Transfer (FRET) or pH-dependent charge transfer (CT) interactions.
Finally, the polymer-coated QDs have been coupled to cell-penetrating
peptides to facilitate intracellular uptake, while subsequent cytotoxicity
tests show no apparent decrease in cell viability