MCI is considered above all to be a prodrome of Alzheimer’s disea

MCI is considered above all to be a prodrome of Alzheimer’s disease and, variably, of other dementias. MCI criteria refer to poor cognitive functioning as assessed at one point in time, thus precluding an appreciation of decline over time; it is thus difficult to differentiate from cohort

effects, low IQ, and education. Later definitions by Petersen et al7 refined the initial concept by referring to memory impairment beyond that expected for both age and education level This has been the working definition adopted by most epidemiological studies. The definition of MCI has been developed within a Perifosine supplier clinical setting. As such, the definition represents a minimal set of distinguishing criteria, the diagnosis resting largely Inhibitors,research,lifescience,medical on the overall clinical picture. Validation of the criteria has been in Inhibitors,research,lifescience,medical terms of their capacity to predict conversion to dementia and/or Alzheimer’s disease. The two are often used interchangeably, which has led to some confusion in the comparison of results across centers. Table I 7,11-18 shows the predictive value of MCI criteria within a clinical setting. Conversion rates to dementia are also noted for some studies. The conversion rate from

MCI to dementia in clinical samples is reported at between 10% and 20%, regardless of age. Together, these studies suggest the predictive validity of the concept within a clinical setting. Inhibitors,research,lifescience,medical These studies are all, however, based on clinical series conducted in specialist Inhibitors,research,lifescience,medical centers, so it is not certain to what extent they represent all cases of MCI found in the general population. Clinical signs and symptoms beyond those cited in the official MCI criteria have also been used for diagnosis, so there is likely to be some differences in case identification between centers. While these studies together suggest the high predictive validity of the concept within a clinical setting, they are unable to provide us with information

on prevalence Inhibitors,research,lifescience,medical and incidence. To date, only a small number of general population studies have been conducted using MCI criteria, giving a range of prevalence estimations from 3% to 19%. There are significant differences in sampling frames, cognitive tests, and drop-out due to mortality Parvulin and refusal between these studies; nonetheless, the majority of authors report rates of around 3% when MCI criteria are strictly applied (Table II).9-24 Subjects in three of the studies reporting higher rates21-23 have received extensive clinical examinations as well as cognitive testing, which may have led to the inclusion of subjects on the basis of clinical criteria beyond those stipulated in the definition of MCI. In three studies,19-21 the authors conclude in their discussion that the criteria are too strict and a large number of subjects are subsequently excluded who would be considered by clinicians as a high-risk group.

It is at least a working hypothesis that motivates further resear

It is at least a working hypothesis that motivates further research more than the less ambitious search for correlations only. Accordingly, research has developed along the lines of looking more closely into specific areas for such explanatory reduction. One very positive development is that neuroscientists and philosophers often collaborate to study not only of vision and Inhibitors,research,lifescience,medical pain but also

a wide spectrum of emotions,61 auditory sensation, olfaction,62 and other topics as well. Two final warning signs need to be heeded, however, concerning the two basic kinds of observation in this area: brain Sotrastaurin supplier activity measurements using certain instruments, and subjects’ reports about their qualia. First, there is a worry that studies Inhibitors,research,lifescience,medical based on fMRI produce

correlations between brain activity measurements and mental state characteristics (such as anxiety, empathy, or distress) that are much higher than to be expected.63 Second, any research into the neuroscience of phenomenal consciousness has to deal with serious problems Inhibitors,research,lifescience,medical of first-person reports. Whether there can be a science of consciousness depends on the old question of whether introspection is a legitimate and reliable method. These problems are serious. While being methodological in nature, one might properly describe them not as traps or gaps, but as breathtaking Inhibitors,research,lifescience,medical abysses instead. There are extensive debates about them in philosophy and cognitive psychology that neuroscientists need to take onboard.42,59,64-69 Conclusion: the limits of skepticism What is interesting

is that much neuroscience of the mind has been provoked by skeptical philosophical arguments. However, as Immanuel Kant said, skeptics are like nomads, who abhor “permanent cultivation of the soil.” The chief function of skepticism is to sharpen our reasoning, and to avoid both dogmatism and naivety. Naivety here consists of an inference from statements about empirical correlations between brain states and qualia to Inhibitors,research,lifescience,medical claims that the former reductively explain the latter. Dogmatism would be to assume that reductive ADAMTS5 physicalism must be true and defended, come what may. Skepticism is no position to ultimately hold either; it is not ultimately tenable or desirable. I have shown how many skeptical arguments suffer from serious weaknesses. In my view, we should view the advancement of the neuroscience of the mind as an arduous task that perhaps requires, as previous developments in science did, revisions of basic concepts and methodologies. Acknowledgments Many thanks to Michael Pauen, Achim Stephan, and two anonymous referees for various suggestions, and to Christopher Evans for linguistic assistance. Work on this article was supported by the Spanish Ministry for Science and Innovation, Reference number FFI 200801559/FISO.

The role of brain oscillations as functional building blocks in s

The role of brain oscillations as functional building blocks in sensory-cognitive processes has gained tremendous importance in recent decades. Event-related oscillations (ERO) in the alpha, beta, gamma, delta,

and theta frequency windows are highly modified throughout the cortex in pathologic brains, in particular from patients with cognitive impairment. However, they can only be characterized as clinical biomarkers by using a wide range of strategies and mathematical parameters. The oscillatory changes in multiple frequency windows and whole cortex should be taken Into consideration by analyzing relevant changes in the amplitude of function-related Inhibitors,research,lifescience,medical oscillations, together with multiple connectivity deficits. The aims of this article are threefold: To FK228 supplier briefly describe the main methods used in the brain research literature, such as evoked/event-related spectra, ERO, Inhibitors,research,lifescience,medical coherence analysis, and phase locking; to illustrate their clinical applications using the example of bipolar disorder

(BD); and to show how this might inform the search for neurophysiologic biomarkers in cognitive impairment.1 To explain the importance, for the design of (differential) diagnostic strategies and (preventive) drug schedules, of analyzing neurophysiologic information in a framework that includes Inhibitors,research,lifescience,medical multiple methods and frequency bands. To propose a practical approach to the analysis and interpretation of brain oscillations. See Box 1 for a glossary of key terms used. Box 1 Alpha response: Oscillatory component of an evoked potential (EP) in the 8-13 Hz frequency range. Amplitude frequency Inhibitors,research,lifescience,medical characteristics (AFC): The spectra of evoked responses in the frequency

domain potentials. Coherence analysis: A mathematical approach to examining the relationship between signals or data sets. Event-related oscillations (ERO): These include event-related potentials (ERP) and induced rhythms. Event-related potential (ERP): The measured Inhibitors,research,lifescience,medical brain response resulting directly from a specific sensory, cognitive, or motor event Evoked frequency response: Dominant maximum in amplitude frequency characteristics. Delta response: Oscillatory component of an evoked potential in the 0.5-3.5 Hz frequency range. Gamma response: Oscillatory component Rutecarpine of an evoked potential in the 30-60 Hz frequency range. Magnetoencephalography: A research and clinical imaging technique for measuring the magnetic fields produced by electrical activity in the brain. Neural oscillation: Rhythmic or repetitive neural activity in the central nervous system. Phase-locked and non phase-locked activity: Non phase-locked activities contain evoked oscillations that are not rigidly time-locked to the moment of stimulus delivery. They include induced alpha, beta, and gamma oscillations that may relate to specific aspects of information processing.

Chemical sterilization with ethylene oxide gas offers the advanta

Chemical sterilization with ethylene oxide gas offers the advantage of effective treatment at ambient temperature and is useful for hydrolytically unstable polymers. Nevertheless, its popularity is decreasing due to the well-known toxicity

and flammability of ethylene oxide. High-energy radiation sterilization method has the advantage of high efficiency, negligible thermal effects. Polymers exhibiting high heats of polymerization tend to cross-link upon radiation, indicating an apparent increase in mechanical stability with increasing radiation doses [39, 40]. Radiation cross-linking does not involve the use of chemical Inhibitors,research,lifescience,medical additives and therefore retaining the biocompatibility of the biopolymer. Also, the modification and sterilization Inhibitors,research,lifescience,medical can be achieved in a single step and hence it is a cost-effective

process to modify biopolymers having their end use specifically in biomedical application. 5.3. Large Scale Production The major challenge of research and development of IPNs for drug delivery is large scale production. There is always a need to scale up laboratory or pilot technologies for eventual commercialization. Inhibitors,research,lifescience,medical It is easier to modify IPNs at laboratory scale for improved performance than at large scale. Maintaining concentration and composition of polymers at large scale is also a challenge. Despite the number of researches and patents for IPN drug delivery technologies, commercialization is still at its early Inhibitors,research,lifescience,medical stage. This is partially due to the fact that most of the research studies are carried out by researchers in academia. Nevertheless, greater effort is needed to bring IPN based drug delivery systems from the experimental level to the pilot scale production and extend their practical applications. This can be achieved by addressing several aspects, which include boosting the selectivity without compromising biocompatibility and stability, optimizing Inhibitors,research,lifescience,medical polymer modification techniques, using the proper

engineering configurations, understanding the mechanism of transport, and using cost-effective materials and methods. 6. Preclinical Studies with IPNs A preclinical study is a stage of research that the IWP-2 begins before clinical trials (testing in humans) and during which important feasibility, iterative testing, and drug safety data is collected. The main goals of preclinical studies are to determine a product’s ultimate safety profile. IPNs based on poly(acrylic acid) and gelatin were evaluated for in vivo biodegradation and release of gentamicin sulphate by Changez et al. [41] In vivo degradation studies demonstrated that the degradation and drug release depend on the composition of hydrogels. It was observed that the rate of in vivo degradation of hydrogels was much lower than in vitro degradation.

Twenty two patients met the inclusion criteria Of these patients

Twenty two patients met the inclusion criteria. Of these patients, we collected data retrospectively and compiled a spreadsheet containing the following information: age, gender, weight, medication (including preparation) comorbidity with autistic spectrum disorders (ASD) as reported by referrer, comorbidity total (other mental health disorders diagnosed at assessment plus ASD as reported by referrer), and dose of medication on first consultation. From this matrix, the dose of medication in milligrams per kilogram was calculated and methylphenidate dose equivalents as described by NICE [National Institute for Health and Clinical Excellence, 2008a] were used. We did not make a

Inhibitors,research,lifescience,medical specialist ASD assessment to confirm or disprove this diagnosis. The weight in kilograms of each patient was checked during the first consultation as well as other physical parameters such as blood pressure (BP), pulse and height. At the same consultation, ADHD symptom severity was assessed Inhibitors,research,lifescience,medical using

the investigator-administered 18-item total ADHD symptom score which is the sum of Inhibitors,research,lifescience,medical the inattentive and hyperactivity/impulsivity subscales from the Conners’ Adult ADHD Rating Scales (CAARS) and has a maximum score of 54 [Conners et al. 1999]. The medication (including preparation) and current prescribed dose were also confirmed. The first set of analyses examined whether there were any factors associated with either the Conners’ score or the dose given. An examination of the distribution of the Conners’ score suggested that this was approximately normally distributed. As a result, the unpaired t-test was used to compare this measure

between patients with and without comorbidity. Inhibitors,research,lifescience,medical There was insufficient data to formally compare between genders. Additional analyses compared the dose between patients with and without comorbidity and also between genders. The dose values were found to have Inhibitors,research,lifescience,medical a positively skewed distribution, and were not normally distributed. Therefore, the Mann—Whitney U-test was used for these analyses. Owing to the distribution of the values, the median was used as the summary Casein kinase 1 measure in preference to the mean. The final GSK1363089 analysis of this data examined the association between age and dose or gender and also between Conners’ score and age. These associations were examined using Pearson correlation. Results Of the 22 patients, only one was female and the mean age was 19.7 (SD = 1.93) years old. The mean Conners’ score was 30.1 (SD = 12.8) and the mean dose of stimulant (mg/kg) was 0.56 (SD = 0.30). The total comorbidity including ASD and other mental health disorders was 31.8% whilst the reported comorbidity by referrer with ASD was 27.3%. The first set of analyses examined the relationships between variables in the dosing dataset and the results are presented in Table 1.

The aging varies from a few minutes (soman) to 22 hours (cyclosar

The aging varies from a few minutes (soman) to 22 hours (cyclosarin).24 As inhibitors of AChE, Organophosphorous compounds, may

act directly or indirectly. Direct inhibitors, such as dichlorvos, are useful without additional metabolic selleck kinase inhibitor modification following absorption, and thus cause rapid symptoms and signs during or after exposure. To be effective, indirect inhibitors such as malathion need to be transformed. All thiono OP pesticides containing a P=S bond need activation by oxidation of the P=S to the P=O group. The symptoms and signs of these compounds appear later, and Inhibitors,research,lifescience,medical last longer. In addition, due to the reversibility of the binding reaction of sarin and soman to CarbE, it

Inhibitors,research,lifescience,medical appears that CarbE is involved in metabolic detoxification of these agents to their corresponding non-toxic metabolites isopropyl methylphosphonic acid (IMPA) and pinacolyl methylphosphonic acid (PMPA).25,26 Organophosphorous compounds poisoning can be diagnosed based on a history of exposure via intentional or accidental oral OP pesticide ingestion, occupational or chemical warfare assult, and clinical manifestations. The enzymes inhibited by OPs provide specific biomarkers of exposure, until the turnover of the enzyme in favorable cases. Accessible AChE is found in red blood cells, Inhibitors,research,lifescience,medical and BChE in the plasma.27 Butyrylcholinesterase is usually preferred as an early biomarker due to its higher presence and Inhibitors,research,lifescience,medical sensitivity than AChE, however, is not as specific as AChE. Screening the red blood cell concentrations of AChE in individuals who are exposed to these agents is essential. Although screening has several limitations, Inhibitors,research,lifescience,medical it can also be used for suspected individuals with nerve agent poisoning. Due to interindividual variations, it does not provide a reliable evidence for low levels of organophosphate exposure at low levels due to interindividual variations. Moreover, control activity levels

are often not available.28 Finally, it is less suitable for retrospective detection of exposure because of new synthesis of enzyme. However, measurement of AChE Cediranib (AZD2171) inhibition is still the most widely used method for the assessment of exposure to nerve agents.26 Grading of OP poisoning severity based on different types of cholinesterases are presented in table 1. Table 1: Severity grading of organophosphorus poisoning based on the cholinesterase inhibition and atropine dose required for atropinization Urine metabolites, or adducts to proteins and DNA can also be used as biomarkers for detecting nerve agent exposure. The main metabolites of nerve agents are alkyl methylphosphonic acids that are found rapidly in the urine, and can be detected up to one week after exposure depending on the extent of eposure.

2006; Chakraborty et al 2009; Ozdemir et al 2009), SP (Atmaca e

2006; Chakraborty et al. 2009; Ozdemir et al. 2009), SP (Atmaca et al. 2008), PD (Kuloglu et al. 2002), and PTSD (Tezcan et al. 2003). Further, studies in populations with anxiety disorders have demonstrated increased activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), xanthine oxidase, glutathione reductase (GSR), and glutathione peroxidase (Kuloglu et al. 2002; Tezcan et al. 2003; Herken et al. 2006; Atmaca et Inhibitors,research,lifescience,medical al. 2008; Ozdemir

et al. 2009). Although these effects are not consistent across all studies (Ozdemir et al. 2009; Hovatta et al. 2010), it suggests that increased levels in oxidative stress do appear in anxiety-disordered populations. Psychological stress appears to be associated with increased O&NS Inhibitors,research,lifescience,medical and brain region specific O&NS induced cellular damage (Hovatta et al. 2010), as demonstrated by increased superoxide production in the mitochondria of rat hippocampus and PFC under chronic mild stress (Lucca et al. 2009), and increased NO production in rat hippocampus (Harvey et al. 2004) and in rat cortex (Olivenza et al. 2000) Inhibitors,research,lifescience,medical in a stress–restress animal model. Psychological stress (e.g., examination stress) is accompanied by an increase in inflammatory markers, lipid peroxidation, oxidative damage to DNA, and reduced antioxidant activity in the plasma (Wadee et al. 2001; Sivonova et

al. 2004). Increased stress levels (e.g., increased perceived workload) and the impossibility to cope with stress have Inhibitors,research,lifescience,medical been associated with elevated 8-hydroxydeoxyguanosine (8-OHdG) levels (Irie et al. 2005). ROS and RNS interact in a bidirectional fashion with proinflammatory cytokine signaling pathways (Hovatta et al. 2010) leading to enhanced O&NS. One example is of neopterin, which is synthesized from macrophages after stimulation by proinflammatory

cytokines (IFN-γ). Production of neopterin increases production of NO through upregulating Inhibitors,research,lifescience,medical inducible nitric oxide synthase (iNOS) gene expression (Maes et al. 2012). Further, the proinflammatory cytokines IL-1β and TNF-α increase superoxide production by stimulating arachidonic acid release, leading to nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation (Chenevier-Gobeaux Oxalosuccinic acid et al. 2007), and activation of proinflammatory transcription factors, including nuclear factor k β (NFkβ) and the cyclic adenosine monophosphate (cAMP) response element binding (CREB) family, appear to regulate the production of O&NS by modulating the activity of NOS, cyclooxygenase 2 (COX2), and NADPH oxidase (Hovatta et al. 2010). Alterations in activity of these particular enzymes have also been linked to anxiety behaviors. For example, enhanced anxiety resulted from the downregulation of NOS through administration of a NOS inhibitor in one study (Masood et al. 2009).

The same concept can be transferred to adult patients with ADHD a

The same concept can be transferred to adult patients with ADHD and/or BD to examine whether treatment-emergent bipolarity (mania in particular) in ADHD patients may also produce higher diagnostic rates of BD. A comparison of such longitudinal results on adults with data obtained from children and adolescents could also help to determine whether a specific group of children and adolescents with PBD and ADHD

symptoms may be at a specific risk of developing bipolar symptoms in adolescence Inhibitors,research,lifescience,medical and later adulthood, and whether this risk could be related to early exposure to stimulants and/or antidepressants. Such research could contribute to developing concepts on how to identify those children and juveniles at risk, and to develop strategies for prevention and treatment. Clinical aspects In considering potential explanations for the co-occurrence Inhibitors,research,lifescience,medical of PBD with ADHD, it was proposed that the presence of PBD symptoms could lead to an artificial increase in diagnostic rates for PBD in

ADHD samples, and that ADHD could be an early and prodromal manifestation of PBD. This proposition was then linked with the findings on treatment-emergent mania – mania triggered by pharmacological treatment Inhibitors,research,lifescience,medical with stimulants and/or antidepressants.16 Following this, it was proposed that ADHD and its associated factors, such as treatment with stimulants, may induce PBD symptoms, and that PBD and ADHD could have

an underlying Akt activity common etiology Inhibitors,research,lifescience,medical as regards genetic and neurobiological risk factors.15 In a recent review analysis, Singh et al have provided evidence that individuals at risk of developing ADHD symptoms may represent early prodromal states of PBD, and that PBD with comorbid ADHD may constitute a particular phenotype of early-onset disturbed mood and impaired affective regulation referred to as early PBD.16 However, these findings are Inhibitors,research,lifescience,medical far from definite, and the extent of comorbidity and the severity of symptom overlap between ADHD and PBD is not yet clear. Moreover, there out are also nonoverlapping symptoms, as depicted in (Figure 3). Figure 3. DSM-IV symptoms of attention deficit-hyperactivity disorder and bipolar mania not showing an overlap. Adapted from ref 23: Wingo AP, Ghaemi SN. A systematic review of rates in diagnostic validity of comorbid adult attention-deficit/hyperactivity disorder … Clarification on these issues is handicapped by the lack of longitudinal data on developmental processes in juvenile PB D, which can in part be put down to problems of feasibility in investigations, one of which constitutes patient recruitment for follow-up measures. In research, the Child Behavior Checklist (CBCL) has frequently been implemented as a tool for the diagnosis of PBD.

In patients with neurodegenerative diseases such as Alzheimer’s d

In patients with neurodegenerative diseases such as Alzheimer’s disease (AD) and behavioral variant frontotemporal dementia (bvFTD), impaired

awareness is common, though it differs in modality and degree (Ecklund-Johnson and Torres 2005; Rankin et al. 2005; Hornberger et al. 2012). Many AD patients are highly aware of their cognitive Inhibitors,research,lifescience,medical deficits early in the disease, but all patients show increasingly inaccurate self-evaluation as the disease progresses (Ecklund-Johnson and Torres 2005). In contrast, early loss of self-awareness is a central feature of bvFTD (Neary et al. 1998). Typically, bvFTD patients describe their personality traits less accurately and are less aware of their specific behavior deficits than AD patients (Eslinger et al. 2005; Rankin et al. 2005; Salmon et al. 2008; Hornberger et al. 2012). bvFTD patients may also be less aware of their cognitive

deficits than AD patients, even when they are less cognitively impaired (Williamson et al. 2010). In fact, bvFTD patients can display substantial deficits in self-awareness Inhibitors,research,lifescience,medical before showing measureable cognitive impairments (Lee et al. 2012), suggesting that self-awareness involves factors beyond the domains tested in a standard neuropsychological battery. This also suggests that the focal anatomy affected early in bvFTD may be more directly involved in self-awareness than the anatomy affected early in AD. Results of functional Inhibitors,research,lifescience,medical and structural neuroimaging studies of self-awareness deficits in neurodegenerative

disease generally confirm these hypotheses (Zamboni and Wilcock 2011). Results, however, Inhibitors,research,lifescience,medical are divergent across studies, likely due to methodological and conceptual differences such as the modality of self-awareness studied, the assessment methods used, or the sample’s characteristics (Markova et al. 2005; Zamboni and Wilcock 2011). While some studies found correlations between self-awareness deficits and right frontal dysfunction (Starkstein et al. 1995; Mendez and Shapira 2005; McMurtray et al. 2006) Inhibitors,research,lifescience,medical and right ventro-medial GDC-0994 chemical structure atrophy (Rosen et al. 2010), others found correlations with lateral temporo-parietal Rebamipide (Salmon et al. 2006; Ruby et al. 2009) or anterior temporal dysfunction (Ruby et al. 2007), and right posterior temporal atrophy (Zamboni et al. 2010). These divergent results may indicate that self-awareness involves a large-scale supramodal neural network (Schmitz and Johnson 2007; Legrand and Ruby 2009), as reported in functional neuroimaging studies investigating the self in healthy individuals, that comprises the medial prefrontal cortex, precuneus/posterior cingulate gyrus, temporo-parietal junction, and temporal poles (Legrand and Ruby 2009). Most previous neuroimaging studies of self-awareness in neurodegenerative disease have focused on whether patients were able to accurately estimate their level of cognitive functioning (Zamboni and Wilcock 2011).

To encapsulate both drugs, they first prepared liposomes before a

To encapsulate both drugs, they first prepared liposomes before active loading of CPT-11 by a pH gradient method, with the protonated CPT-11 retained in liposomes after complex formation with FOA. Mice treated with coloaded liposomes had increased survival compared to the combination with separate liposomes. However, the therapeutic efficacy was lower than with liposomes loaded with FOA only, probably because the FOA content had to be lowered for CPT-11 coloading, further demonstrating the difficulty of reproducing a synergy with liposomes relative to free drugs.

When tested in phase I trial with acute leukemia patients, the 5:1 ratio was maintained Inhibitors,research,lifescience,medical in plasma for 24h, and GW9662 supplier CPX-351 induced complete responses in 9 out of 43 patients [24]. The same group developed irinotecan: floxuridine liposomes (CPX-1,

1:1 molar ratio). In phase I clinical trial they demonstrated that the drug ratio was maintained in plasma up to 12h after Inhibitors,research,lifescience,medical infusion and showed positive clinical responses in patients with colorectal cancer [25]. It is noteworthy that the high therapeutic efficacy of liposomes encapsulating two anticancer drugs was always correlated with the maintenance of their synergistic molar ratio in plasma, in animal models [266] as well Inhibitors,research,lifescience,medical as in cancer patients [24, 25, 264] indicating optimization of drug loading and liposomal stability as primary concerns for effective combination therapy. Ko et al. codelivered the proapoptotic peptide D-(KLAKKLAK)2 and the Bcl-2 antisense oligodeoxynucleotide G3139 [267]. The authors took the advantage of the electrostatic properties of Inhibitors,research,lifescience,medical these therapeutic molecules to codeliver them by formation of a negatively charged complex between the peptide and G3139 before mixing with positively charged liposomes. Inhibitors,research,lifescience,medical Intratumoral injection of coloaded liposomes led to an enhanced tumor growth suppression. Finally, the combined liposomal delivery of magnetic fluid hyperthermia and photodynamic therapy using magnetic fluid and zinc phthalocyanine as the photosensitizer demonstrated superior

toxicity in vitro of combined light and magnetic stimuli over their separate applications suggesting a new treatment modality for enhanced tumor therapy [268]. 5. Tumor Stimuli-Triggered PAK6 PEG Release The addition of PEG to the liposome surface was reported to decrease the interaction of the ligand-targeted liposomes with their ligand, either when small molecules were conjugated to the liposome surface [269] or with antibody-targeted liposomes [48, 118] by steric hindrance of the surface ligand. Moreover, PEGylation decreases targeted liposomal accumulation and drug release [270]. Finally, for gene delivery, PEGylation has been shown to decrease intracellular trafficking of DNA [271].