Correction: An impedimetric sensor based on molecularly imprinted nanoparticles for the determination of trypsin in artificial matrices - towards point-of-care diagnostics.

Correction for 'An impedimetric sensor based on molecularly imprinted nanoparticles for the determination of trypsin in artificial matrices - towards point-of-care diagnostics' by Sabrina Di Masi et al., Anal. Methods, 2024, 16, 742-750, https://doi.org/10.1039/D3AY01762A.

An impedimetric sensor based on molecularly imprinted nanoparticles for the determination of trypsin in artificial matrices - towards point-of-care diagnostics.

A high-performance impedimetric sensing platform was designed to detect proteins by employing molecularly imprinted polymeric nanoparticles (nanoMIPs) as selective receptors. This was achieved via the combination of the nanoMIPs with a self-assembled thioctic acid (SAM-TA) monolayer onto screen-printed gold electrodes, providing stable covalent attachment of the selective binder to the transducer. Taguchi design has been modelled to achieve the optimal level of sensor fabrication parameters and to maximise the immobilisation of nanoMIPs and their response (e.g. the response of imprinted polymers compared with the non-imprinted control). The developed sensor was tested towards a range of concentrations of trypsin dissolved in ammonium acetate (pH = 6) and showed promising applicability in artificial saliva, with a recovery percentage between 103 and 107%.

Distinctive Electric Properties of Group 14 Oxides: SiO2, SiO, and SnO2.

The oxides of group 14 have been widely used in numerous applications in glass, ceramics, optics, pharmaceuticals, and food industries and semiconductors, photovoltaics, thermoelectrics, sensors, and energy storage, namely, batteries. Herein, we simulate and experimentally determine by scanning kelvin probe (SKP) the work functions of three oxides, SiO2, SiO, and SnO2, which were found to be very similar. Electrical properties such as electronic band structure, electron localization function, and carrier mobility were also simulated for the three crystalline oxides, amorphous SiO, and surfaces. The most exciting results were obtained for SiO and seem to show Poole-Frankel emissions or trap-assisted tunneling and propagation of surface plasmon polariton (SPP) with nucleation of solitons on the surface of the Aluminum. These phenomena and proposed models may also describe other oxide-metal heterojunctions and plasmonic and metamaterials devices. The SiO2 was demonstrated to be a stable insulator interacting less with the metals composing the cell than SnO2 and much less than SiO, configuring a typical Cu/SiO2/Al cell potential well. Its surface charge carrier mobility is small, as expected for an insulator. The highest charge carrier mobility at the lowest conduction band energy is the SnO2's and the most symmetrical the SiO's with a similar number of electron holes at the conduction and valence bands, respectively. The SnO2 shows it may perform as an n-type semiconductor.

Patients' Perspectives on Determinants Avoidable Hospitalizations: Development and Validation of a Questionnaire.

Ambulatory care sensitive conditions (ACSC) can be avoided through effective care in the ambulatory setting. Patients are the most qualified individuals to express the social and individual contexts of their own experience. Thus, understanding why potentially preventable hospitalizations occur is important to develop patient-centred policies or interventions that may reduce them. This study aims to develop and validate a questionnaire to capture the patients' perspective on the causes of the hospitalizations for ACSC. The development of a new questionnaire involved four phases: a literature review, face validity, pre-test, and validation. We conducted a three-step face validity verification to confirm the relevance of the identified determinants and to collect determinants not previously identified by interviewing healthcare providers, representatives of patients' associations, and patients. Determinants were identified through the literature review predominantly in the "Healthcare Access", "Disease self-management", and "Social Support" domains. The validated resulting questionnaire comprises 25 questions, distributed by two dimensions (individual/contextual) covering seven domains and 20 determinants of ACSC hospitalization. Currently, there are no validated instruments as comprehensive and easy to use as the one described in this paper. This questionnaire should provide a base for further language/context validations.

Solid-phase synthesis of imprinted nanoparticles as artificial antibodies against the C-terminus of the cannabinoid CB1 receptor: exploring a viable alternative for bioanalysis.

The production of artificial anti-CB1 antibodies in nanoparticle format is described using the solid-phase imprinting approach. Instead of whole protein imprinting, a linear C-terminus sequence of the receptor comprising 15 amino acids (458-KVTMSVSTDTSAEAL-472) has been used as template, in accordance with the epitope imprinting approach. This sequence is located intracellularly, and it is involved in coupling to Gi/o proteins, being responsible for CB1 receptor desensitisation and internalisation. Developed molecularly imprinted materials were found to be in the nanometre scale, with a particle size of 126.4 ± 10.5 nm at pH 3 (25 ºC) and spherical shape. It was also observed that the size was sensible to temperature changes being reduced to 106.3 ± 15.2 nm at 35 °C. Lower critical solution temperature of this polymer was found to be ≈ 33.4 °C. The affinity and selectivity of the artificial antibody were assessed through dot blot and Western blot experiments. For the latter, recombinant fusion proteins GST-CB1414-472 and GST-CB1414-442 were produced to work respectively as target and negative control proteins. The control protein did not carry the target epitope for being devoid of last 30 amino acids at the C-terminus. The results demonstrated that the anti-CB1 material recognised selectively the target protein, thanks to the presence of the 15-amino acid sequence selected as epitope, which revealed that binding occurred at the C-terminus of the receptor itself. The methodology presented may pave the way for the development of novel imprinted nanomaterials for other proteins included in the superfamily of the G-protein-coupled receptors (GPCR).

Nonsemantic word graphs of texts spanning ∼ 4500 years, including pre-literate Amerindian oral narratives.

Non-semantic word graphs obtained from oral reports are useful to describe cognitive decline in psychiatric conditions such as Schizophrenia, as well as education-related gains in discourse structure during typical development. Here we provide non-semantic word graph attributes of texts spanning approximately 4500 years of history, and pre-literate Amerindian oral narratives. The dataset assessed comprises 707 literary texts representative of 9 different Afro-Eurasian traditions (Syro-Mesopotamian, Egyptian, Hinduist, Persian, Judeo-Christian, Greek-Roman, Medieval, Modern and Contemporary), and Amerindian narratives (N = 39) obtained from a single ethnic group from South America (Kalapalo, N = 18), or from a mixed ethnic group from South, Central and North America (non-Kalapalo, N = 21). The present article provides detailed information about each text or narrative, including measurements of four graph attributes of interest: number of nodes (lexical diversity), repeated edges (short-range recurrence), largest strongly connected component (long-range recurrence), and average shortest path (graph length).

Molecularly Imprinted Nanoparticles (NanoMIPs) Selective for Proteins: Optimization of a Protocol for Solid-Phase Synthesis Using Automatic Chemical Reactor.

Molecularly imprinted polymer nanoparticles (nanoMIPs) are receiving broad interest as robust and highly selective synthetic receptors for a variety of molecules. Due to their stability, inexpensive synthesis and easy implementation, they are considered a promising alternative to antibodies in sensors, diagnostics and separation applications. The most challenging targets for the production of synthetic receptors are proteins due to their fragile nature and the multitude of possible binding sites in their structure. Herein, we describe the modification and optimization of the protocol for synthesis of nanoMIPs with specificity for proteins using the prototype of an automated solid-phase synthesizer. Using an automated system gives an advantage for the simple, fast and fully controlled, reproducible production of nanoMIPs. The molecular imprinting in the reactor is performed using a template covalently immobilized on a solid support, in mild conditions suitable for preserving protein native structure. The validation of the protocol was made by assessing the ability to regenerate a solid-phase, and by measuring affinity and specificity of nanoparticles. As a model protein, we have chosen trypsin since its enzymatic activity can be easily monitored by using a commercial colorimetric assay. Different protocols were tested for their ability to improve the yield of high affinity nanoparticles in the final elution.

The History of Writing Reflects the Effects of Education on Discourse Structure: Implications for Literacy, Orality, Psychosis and the Axial Age.

BACKGROUND: Graph analysis detects psychosis and literacy acquisition. Bronze Age literature has been proposed to contain childish or psychotic features, which would only have matured during the Axial Age (∼800-200 BC), a putative boundary for contemporary mentality. METHOD: Graph analysis of literary texts spanning ∼4,500 years shows remarkable asymptotic changes over time. RESULTS: While lexical diversity, long-range recurrence and graph length increase away from randomness, short-range recurrence declines towards random levels. Bronze Age texts are structurally similar to oral reports from literate typical children and literate psychotic adults, but distinct from poetry, and from narratives by preliterate preschoolers or Amerindians. Text structure reconstitutes the "arrow-of-time", converging to educated adult levels at the Axial Age onset. CONCLUSION: The educational pathways of oral and literate traditions are structurally divergent, with a decreasing range of recurrence in the former, and an increasing range of recurrence in the latter. Education is seemingly the driving force underlying discourse maturation.

Direct detection of small molecules using a nano-molecular imprinted polymer receptor and a quartz crystal resonator driven at a fixed frequency and amplitude.

Small molecule detection is of wide interest in clinical and industrial applications. However, its accessibility is still limited as miniaturisation and system integration is challenged in reliability, costs and complexity. Here we combined a 14.3 MHz quartz crystal resonator (QCR), actuated and analysed using a fixed frequency drive (FFD) method, with a nanomolecular imprinted polymer for label-free, realtime detection of N-hexanoyl-L-homoserine lactone (199 Da), a gram-negative bacterial infection biomarker. The lowest concentration detected (1 µM) without any optimisation was comparable with that of a BIAcore SPR system, an expensive laboratory gold standard, with significant enhancement in sensitivity and specificity beyond the state-of-the-art QCR. The analytical formula-based FFD method can potentially allow a multiplexed "QCR-on-chip" technology, bringing a paradigm shift in speed, accessibility and affordability of small molecule detection.

Florfenicol Binding to Molecularly Imprinted Polymer Nanoparticles in Model and Real Samples.

A simple and straightforward technique for coating microplate wells with molecularly imprinted polymer nanoparticles (nanoMIPs) to develop assays similar to the enzyme-linked immunosorbent (ELISA) assay to determine and quantify florfenicol (FF) in real food samples such as liquid milk and salmon muscle is presented here. The nanoMIPs were synthesized by a solid-phase approach with an immobilized FF (template) and characterized using dynamic light scattering, a SPR-2 biosensor system and transmission electron microscopy. Immobilization of nanoMIPs was conducted by preparing a homogenous solution of FF-nanoMIPs in water mixed with polyvinyl alcohol (PVA) 0.2% (w/v) in each well of a microplate. The detection of florfenicol was achieved in competitive binding experiments with a horseradish peroxidase-florfenicol (FF-HRP) conjugate. The assay made it possible to measure FF in buffer and in real samples (liquid milk and salmon muscle) within the range of 60-80 and 90-100 ng/mL, respectively. The immobilized nanoMIPs were stored for six weeks at room temperature and at 5 °C. The results indicate good signal recovery for all FF concentrations in spiked milk samples, without any detrimental effects to their binding properties. The high affinity of nanoMIPs and the lack of a requirement for cold chain logistics make them an attractive alternative to traditional antibodies used in ELISA.

Probing Peptide Sequences on Their Ability to Generate Affinity Sites in Molecularly Imprinted Polymers.

An array of 4000 defined and addressable tripeptides on a polymer-coated glass slide is used to synthesize molecularly imprinted polymer (MIP) nanoparticles. This work is undertaken to systematically probe the impact of the peptide sequence on the ability to generate affinity MIPs. The polymer affinity is assessed by measuring the fluorescence of bound MIP nanoparticles at each peptide spot on the surface after washing the array to remove any low-affinity polymer. The generic composition commonly used in the preparation of MIPs against proteins seems to be equally suitable for imprinting hydrophobic and hydrophilic tripeptides. The amino acids frequently contributing to the formation of high-affinity MIPs include T, F, D, N, Y, W, and P. The amino acids that rarely contribute to the formation of high-affinity interactions with MIPs are G, V, A, L, I, and M. These observations are confirmed by computational modeling. The basic technique proposed here may be applicable in optimizing polymer compositions for the production of high-affinity MIPs or, more specifically, for the selection of appropriate amino acid sequences when peptide epitopes are used instead of whole protein imprinting.

Epitope approach in molecular imprinting of antibodies.

Herein an approach to prepare molecularly imprinted polymer nanoparticles (nanoMIPs) with specific binding affinity for antibodies is reported. The process relied on the covalent immobilization of the template (whole immunoglobulin G (IgG), Fc domain of human IgG and peptide epitope) onto the surface of a solid support, polymerization and affinity separation of nanoMIPs. The binding between nanoMIPs and their corresponding templates was analyzed and evaluated as being in sub-nanomolar and nano-molar range. The nanoMIPs prepared for Fc domain and epitope demonstrated a specific recognition of both human and goat IgGs, therefore they could be considered as a synthetic analogue of protein A and benefit from its intrinsic stability, short time and low cost of preparation.

A novel capacitive sensor based on molecularly imprinted nanoparticles as recognition elements.

Molecularly Imprinted Polymers (MIPs) are synthetic receptors capable of selective binding to their target (template) molecules and, hence, are used as recognition elements in assays and sensors as a replacement for relatively unstable enzymes and antibodies. Herein, we describe a manufacturing-friendly protocol for integration of MIP nanoparticles (nanoMIPs) with a (label-free) capacitive sensor. The nanoMIPs were produced by solid-phase synthesis for two templates with different sizes and properties, including a small molecule tetrahydrocannabinol (THC) and a protein (trypsin). NanoMIPs were deposited on the surface of the sensor and the change in capacitance (ΔC) upon binding of the target was measured. The significant improvement in the selectivity and limit of detection (one order of magnitude compared to previously used MIP microparticles) can be attributed to their increased surface-to-volume ratio and higher specificity of the nanoMIPs produced by the solid-phase method. The methodology described is also compatible with common sensor fabrication approaches, as opposed to methods involving in situ MIP polymerisation. The proposed sensor shows high selectivity, fast sensor response (45 min including injection, regeneration and re-equilibration with running buffer), and straightforward data analysis, which makes it viable for label-free monitoring in real-time. The set of targets assessed in this manuscript shows the general applicability of the biosensor platform.

Specific Drug Delivery to Cancer Cells with Double-Imprinted Nanoparticles against Epidermal Growth Factor Receptor.

Epidermal growth factor receptor (EGFR), a tyrosine kinase receptor, is over-expressed in many tumors, including almost half of triple-negative breast cancers. The latter belong to a very-aggressive and drug-resistant form of malignancy. Although humanized anti-EGFR antibodies can work efficiently against these cancers both as monotherapy and in combination with genotoxic drugs, instability and high production costs are some of their known drawbacks in clinical use. In addition, the development of antibodies to target membrane proteins is a very challenging task. Accordingly, the main focus of the present work is the design of supramolecular agents for the targeting of membrane proteins in cancer cells and, hence, more-specific drug delivery. These were produced using a novel double-imprinting approach based on the solid-phase method for preparation of molecularly imprinted polymer nanoparticles (nanoMIPs), which were loaded with doxorubicin and targeted toward a linear epitope of EGFR. Additionally, upon binding, doxorubicin-loaded anti-EGFR nanoMIPs elicited cytotoxicity and apoptosis only in those cells that over-expressed EGFR. Thus, this approach can provide a plausible alternative to conventional antibodies and sets up a new paradigm for the therapeutic application of this class of materials against clinically relevant targets. Furthermore, nanoMIPs can promote the development of cell imaging tools against difficult targets such as membrane proteins.

Modulation of Quorum Sensing in a Gram-Positive Pathogen by Linear Molecularly Imprinted Polymers with Anti-infective Properties.

We describe the development, characterization, and biological testing of a new type of linear molecularly imprinted polymer (LMIP) designed to act as an anti-infective by blocking the quorum sensing (QS) mechanism and so abrogating the virulence of the pathogen Streptococcus pneumoniae. The LMIP is prepared (polymerized) in presence of a template molecule, but unlike in traditional molecular imprinting approaches, no cross-linker is used. This results in soluble low-molecular-weight oligomers that can act as a therapeutic agent in vitro and in vivo. The LMIP was characterized by mass spectrometry to determine its monomer composition. Fragments identified were then aligned along the peptide template by computer modeling to predict the possible monomer sequence of the LMIP. These findings provide a proof of principle that LMIPs can be used to block QS, thus setting the stage for the development of LMIPs a novel drug-discovery platform and class of materials to target Gram-positive pathogens.

Biomimetic Silica Nanoparticles Prepared by a Combination of Solid-Phase Imprinting and Ostwald Ripening.

Herein we describe the preparation of molecularly imprinted silica nanoparticles by Ostwald ripening in the presence of molecular templates immobilised on glass beads (the solid-phase). To achieve this, a seed material (12 nm diameter silica nanoparticles) was incubated in phosphate buffer in the presence of the solid-phase. Phosphate ions act as a catalyst in the ripening process which is driven by differences in surface energy between particles of different size, leading to the preferential growth of larger particles. Material deposited in the vicinity of template molecules results in the formation of sol-gel molecular imprints after around 2 hours. Selective washing and elution allows the higher affinity nanoparticles to be isolated. Unlike other strategies commonly used to prepare imprinted silica nanoparticles this approach is extremely simple in nature and can be performed under physiological conditions, making it suitable for imprinting whole proteins and other biomacromolecules in their native conformations. We have demonstrated the generic nature of this method by preparing imprinted silica nanoparticles against targets of varying molecular mass (melamine, vancomycin and trypsin). Binding to the imprinted particles was demonstrated in an immunoassay (ELISA) format in buffer and complex media (milk or blood plasma) with sub-nM detection ability.

O Cromo sérico baixo é raro em doentes submetidos a gastrostomia endoscópica para nutrição entérica de longa duração / Low serum chromium is rare in patients that underwent endoscopic gastrostomy for long term enteral feeding

ABSTRACT BACKGROUND Patients that underwent Percutaneous Endoscopic Gastrostomy (PEG) present with protein-energy malnutrition. Trace elements are required in small quantities and Chromium (Cr) displays a major role in the metabolism. OBJECTIVE This study aims to evaluate Cr levels and its relationship with serum proteins, BMI and underlying diseases during the first 3 months of PEG feeding. METHODS Prospective observational study during 3-months, when PEG was performed (T0), after 4 (T1), and 12 weeks (T3). Initial evaluation included: age, gender, underlying disease, NRS-2002, BMI, serum albumin, transferrin and Cr concentration. At T1 and T3 a blood sample was collected for Cr, albumin and transferrin. A Graphite Furnace Atomic Absorption Spectroscopy was used to assess Cr. According with the underlying disease, patients were divided into two groups: head and neck cancer (HNC) and neurological dysphagia (ND). All patients were fed with homemade meals. RESULTS A one hundred and twenty-nine patients (80 males), 26-95 years old were studied: HNC-52; ND-77. The observed data included low mean values of BMI from 71 patients; low Cr-8, low albumin-70, low transferrin-85 and 57 with both proteins low. Albumin was associated with survival time ( P =0.024) and there was a significant correlation between albumin and Cr (r=0.217, P =0.012). A good evolution of Cr and proteins values was observed, with no low Cr levels at T3. CONCLUSION Low serum Cr is rare in PEG-patients, with no relationship to other studied parameters. For the minority of patients displaying low Cr before gastrostomy, homemade PEG meals seem to be effective.

RESUMO CONTEXTO Doentes submetidos a gastrostomia endoscópica percutânea apresentam desnutrição energético-proteica. Os elementos traço são necessários em pequenas quantidades e o Cromo (Cr) tem um papel importante no metabolismo. OBJECTIVO Pretendeu-se avaliar os níveis séricos de Cr e sua relação com as proteínas séricas, índice de massa corporal (IMC) e as doenças subjacentes nos primeiros 3 meses de alimentação por gastrostomia endoscópica percutânea. MÉTODOS Estudo prospetivo observacional durando 3 meses: avaliações no momento do procedimento (T0), após 4 (T1) e 12 semanas (T3). A avaliação inicial incluiu: idade, gênero, doença subjacente, Nutricional Risk Screening 2002 , IMC, concentração sérica de Cr, albumina e transferrina. Em T1 e T3, colheu-se sangue para Cr, albumina e transferrina. Para avaliação do Cr, utilizou-se espectrometria de absorção atómica em forno de grafite. Classificaram-se os doentes em dois grupos: neoplasias cervicofaciais (NCF) e disfagia neurológica (DN). Todos foram alimentados com alimentos de preparação doméstica. RESULTADOS Avaliaram-se 129 doentes (80 homens), entre 26-95 anos: NCF-52; DN-77. Encontraram-se valores baixos do IMC-71; Cr-8, albumina-70, transferrina-85 e 57 com ambas as proteínas baixas. Identificou-se correlação com significado estatístico entre a albumina e Cr (r=0,217, P =0,012) e entre a albumina e tempo de sobrevivência ( P =0,024). Foi observada boa evolução do Cr e proteínas, não sendo encontrados valores baixos de Cr em T3. CONCLUSÃO O Cr baixo é raro em doentes com gastrostomia endoscópica percutânea, sem relação com outros parâmetros, incluindo o tipo de doença subjacente. Para a minoria dos doentes com Cr baixo antes da gastrostomia, refeições de preparação doméstica parecem ser adequadas.

Molecularly imprinted nanoparticles grafted to porous silica as chiral selectors in liquid chromatography.

The work presented here explores the grafting of molecularly imprinted nanoparticles (MIN) on silica beads for the development of new chiral stationary phases (CSP). Both solid-phase imprinting and precipitation polymerisation were tested for MIN synthesis though the latter approach was the only one that provided efficient chiral selectors. MIN particles were prepared by iniferter polymerisation initiated by UV radiation, using itaconic acid as functional monomer and ethylene dimethacrylate as cross-linker. This resulted in particles with an average size of 249.0±4.0nm which were covalently immobilised onto chromatographic silica beads. The resultant CSP based on the composite silica beads-MIN was capable of resolving the racemate of the antidepressant drug citalopram and also separating its major metabolites by liquid chromatography, with better efficiency and peak symmetry than other MIP based CSP. The methodology presented here allowed for the quantification of the pharmacologically active enantiomer (+)-(S)-citalopram (SCIT) and its main metabolites (+)-(S)-desmethylcitalopram (SDCIT) and (+)-(S)-didesmethylcitalopram (SDDCIT) in urine, registering mean recoveries that ranged from 91.5 to 103.7% with RSD values that were below 10% in all tested concentration levels (0.1, 0.75 and 5µgmL-1), which confirmed method suitability for the intended application.

LOW SERUM CHROMIUM IS RARE IN PATIENTS THAT UNDERWENT ENDOSCOPIC GASTROSTOMY FOR LONG TERM ENTERAL FEEDING.

BACKGROUND: Patients that underwent Percutaneous Endoscopic Gastrostomy (PEG) present with protein-energy malnutrition. Trace elements are required in small quantities and Chromium (Cr) displays a major role in the metabolism. OBJECTIVE: This study aims to evaluate Cr levels and its relationship with serum proteins, BMI and underlying diseases during the first 3 months of PEG feeding. METHODS: Prospective observational study during 3-months, when PEG was performed (T0), after 4 (T1), and 12 weeks (T3). Initial evaluation included: age, gender, underlying disease, NRS-2002, BMI, serum albumin, transferrin and Cr concentration. At T1 and T3 a blood sample was collected for Cr, albumin and transferrin. A Graphite Furnace Atomic Absorption Spectroscopy was used to assess Cr. According with the underlying disease, patients were divided into two groups: head and neck cancer (HNC) and neurological dysphagia (ND). All patients were fed with homemade meals. RESULTS: A one hundred and twenty-nine patients (80 males), 26-95 years old were studied: HNC-52; ND-77. The observed data included low mean values of BMI from 71 patients; low Cr-8, low albumin-70, low transferrin-85 and 57 with both proteins low. Albumin was associated with survival time ( P =0.024) and there was a significant correlation between albumin and Cr (r=0.217, P =0.012). A good evolution of Cr and proteins values was observed, with no low Cr levels at T3. CONCLUSION: Low serum Cr is rare in PEG-patients, with no relationship to other studied parameters. For the minority of patients displaying low Cr before gastrostomy, homemade PEG meals seem to be effective.

Serum zinc evolution in dysphagic patients that underwent endoscopic gastrostomy for long term enteral feeding.

BACKGROUND AND OBJECTIVES: Patients undergoing endoscopic gastrostomy (PEG) present with protein-energy malnutrition (PEM) but little is known about zinc status. Our aim was to evaluate serum zinc, its relationship with serum proteins and with the nature of the underlying disorder, during the first 3 months of PEG feeding. METHODS AND STUDY DESIGN: Prospective observational study during a 3-month period after gastrostomy. Data was collected at initial PEG procedure (T0), after 4 (T1) and 12 weeks (T3). Initial evaluation included: age, gender, disorder causing dysphagia, Neurological Dysphagia (ND) or Head and Neck Cancer (HNC), NRS-2002, BMI, albumin, transferrin, zinc. At T1 and T3, a blood sample was collected for zinc, albumin, transferrin. Serum zinc evaluation was performed with ICP-AES - Inductively Coupled Plasma-Atomic Emission Spectroscopy. Patients were fed with homemade meals. RESULTS: A total of 146 patients (89 males), 21-95 years were studied: HNC-56, ND-90 and low BMI in 78. Initial low zinc in 122; low albumin in 77, low transferrin in 94; low values for both proteins in 66. Regarding the serum protein evolution, their levels increase T0-T3, most patients reaching normal values. zinc has a slower evolution, most patients still displaying low zinc at T3. Significant differences between the 3 moments for zinc (p=0.011), albumin (p<0.0001) and transferrin (p=0.014). CONCLUSION: PEG patients are prone to PEM and zinc deficiency. Most patients present decreased zinc, suggesting that zinc deficiency is common in PEG candidates and is not corrected during 3 months of enteral feeding. Zinc deficiency should be expected and teams taking care of PEG patients should use zinc supplementation.