Nanotechnology in the development of novel functional foods or their package. An overview based in patent analysis

In recent years nanotechnology has become a significant component in food industry. It is present in all food chain steps, from the design of new ingredients or additives, to the most modern systems of food quality methods or packaging, demonstrating the great potential of this new technology in a sector as traditional as food. However, while interest by industry in nanotechnology increases, the rejection by consumers, concerned about the potential risk, does too. The aim of this review is to evaluate the development of food nanotechnology by means of a patent analysis, highlighting current applications of nanotechnology along the whole food chain and contextualizing this evolution in the social scene.

Gated silica mesoporous supports for controlled release and signaling applications

Blending molecular and supramolecular advances with materials science has resulted in recent years in the development of new organic-inorganic hybrid materials displaying innovative functionalities. One appealing concept in this field is the development of gated nanodevices. These materials are prepared by grafting molecular or supramolecular caps onto the external surface of mesoporous inorganic scaffolds loaded with a particular cargo. The caps or "gates" can then be opened and the cargo delivered at will upon the application of a given stimulus. In this Account, we report some of the recent advances we have made in designing such materials for drug delivery and as new chromo-fluorogenic probes. For controlled release applications, we have prepared capped hybrid mesoporous supports capable of being selectively opened by applying certain physical and chemical stimuli. We report examples of gated materials opened by changes in pH (using polyamines as caps), light (employing spiropyran derivatives or gold nanoparticles), and temperature (using selected paraffins). We also report gated materials opened by enzymes that cleave capping molecules based on lactose, hydrolyzed starch, and peptides. The use of enzymes is especially appealing because molecular caps built of enzyme-specific sequences made of peptides or other cleavable molecules could allow on-command delivery of drugs and biomolecules in specialized contexts. In the second part of the manuscript, we revisit the possibility of using hybrid gated nanomaterials as sensory systems. In such systems, when target analytes interact with the cap, their presence triggers the transport of a dye from pores to the solution, resulting in a chromo-fluorogenic signal that allows their detection. Two approaches are possible. In the first one, pores remain open and the dye can diffuse into the solution, until the presence of a target analyte binds to receptors in the caps and closes the gate. In the second approach, the caps are closed and the presence of a target analyte induces pore opening and dye delivery. One of the most interesting properties of these sensory hybrid materials is their inherent amplification features, because few target analyte molecules can modulate the transport of a significant amount of dye molecules within the porous network. We describe such systems for the recognition and sensing of anionic (ATP, long-chain carboxylates, anionic surfactants, borate, and oligonucleotides), cationic (methylmercury), and neutral (nerve agent simulants and sulfathiazole) species.

Recent patents in food nanotechnology

Nanotechnology is a multidisciplinary field of current interest. The huge possibilities in most industries are making nanoscience grow at a rapid pace, but what is the real impact of nanotechnology in a traditional industry such as food? The study of patents published in the last 20 years provides the answer, and the results are quite surprising; the food industry is the fifth largest sector in terms of patents related to nanotechnology.

Enzyme-responsive intracellular controlled release using nanometric silica mesoporous supports capped with "saccharides"

The synthesis of new capped silica mesoporous nanoparticles for on-command delivery applications is described. The gate-like functional hybrid systems consisted of nanoscopic MCM-41-based materials functionalized on the pore outlets with different "saccharide" derivatives and a dye contained in the mesopores. A series of hydrolyzed starch products as saccharides were selected. The mesoporous silica nanoparticles S1, S2, and S3 containing the grafted starch derivatives Glucidex 47, Gludicex 39, and Glucidex 29 were synthesized. Additionally, for comparative purposes solid S4 containing lactose was prepared. Delivery studies in pure water in the presence of pancreatin or β-d-galactosidase were carried out for S1-S3 and S4, respectively. S1, S2, and especially S3 showed very low release in the absence of enzyme, but displayed cargo delivery in the presence of the corresponding enzyme. Moreover, nanoparticles of S1 were used to study the controlled release of the dye in intracellular media. Cell viability assays using HeLa and LLC-PK1 cells indicated that S1 nanoparticles were devoid of unspecific cell toxicity. The endocytosis process for S1 nanoparticle internalization in HeLa cells was confirmed, and the anchored starch was degraded by the lysosomal enzymes. Furthermore, a new mesoporous silica nanoparticle functionalized with Glucidex 47 and loaded with a cytotoxic, S1-DOX, was developed. The cell viability with S1-DOX decreased due to the internalization of the nanoparticle, enzyme-dependent opening of the saccharide molecular gate and the consequent release of the cytotoxic agent. As far as the authors know, this is the first example of enzyme-induced in-cell delivery using capped silica mesoporous nanoparticles.

Controlled delivery systems using antibody-capped mesoporous nanocontainers

This paper describes the design of new controlled delivery systems consisting of a mesoporous support functionalized on the pore outlets with a certain hapten able to interact with an antibody that acts as a nanoscopic cap. The opening protocol and delivery of the entrapped guest is related by a displacement reaction involving the presence in the solution of the antigen to which the antibody is selective. As a proof-of-the-concept, the solid MCM-41 was selected as support and was loaded with the dye [Ru(bipy)(3)]Cl(2). Then a suitable derivative of the hapten 4-(4-aminobenzenesulfonylamino)benzoic acid was anchored on the outer surface of the mesoporous support (solid S1). Finally the pores were capped with a polyclonal antibody for sulfathiazole (solid S1-AB). Delivery of the dye in the presence of a family of sulfonamides was studied in phosphate-buffered saline (PBS; pH 7.5). A selective uncapping of the pores and dye delivery was observed for sulfathiazole. This delivery behavior was compared with that shown by other solids that were prepared as models to assess the effect of the hapten and its interaction with antibody in the dye delivery control in the presence of the antigen.

Results of liver transplantation at the Cuban Center for Medical and Surgical Research

From July 4, 1999, when a liver transplantation program was started in Cuba, to December 30, 2007, we performed 125 procedures in 115 patients. The most frequent reasons for transplantation were cirrhosis caused by hepatitis C virus (29%) and alcoholic cirrhosis (17.2%). Two patients received simultaneous liver-kidney transplants. Sixty-seven patients were males, and the patient ages ranged from 12 to 74 years. The average surgical time was 6 hours, and cold ischemia time was 4 to 14 hours. The average blood consumption was 1630 mL; 2900 mL of plasma and 8 units of platelets were used in 7 cases. Immunosuppression was mainly cyclosporine, mycophenolate mofetil, and prednisone. Acute cellular rejections were treated in almost all cases with 3 doses of methylprednisolone. The most frequent complications were biliary (15%), hepatic arterial thrombosis (6%), postsurgical bleeding (8%), acute cellular rejection (20%), and ductopenic rejection (2%). The overall 1-year survival was 74.7%.

Controlled release of vitamin B2 using mesoporous materials functionalized with amine-bearing gate-like scaffoldings

A study on the controlled release of vitamin B(2) in pure water from mesoporous silica-based materials containing a pH- and anion-controlled nano-supramolecular gate-like ensembles built up by anchoring suitable polyamines on the external surface is reported (solid S1). This solid contains the vitamin (the delivered molecule) onto the pores, whereas the amine-based gate-like ensemble is anchored on the pore outlets. To obtain solid S1 the mesoporous MCM-41 support was first synthesized using tetraethyl orthosilicate (TEOS) as hydrolytic inorganic precursor and the surfactant hexadecyltrimethylammonium bromide (CTAB) as porogen species. Calcination of the mesostructured phase resulted in the starting solid. Then, first the vitamin and the latter an excess of 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane were added to the suspension containing the MCM-41 scaffolding and stirred. Solid S1 was characterized using standard solid state procedures. It was found that the functionalization process and the inclusion of the vitamin on the pores do not modify the mesoporous structure of the starting material. Delivery studies in water were carried out at pH 2 and 7. At pH 2 all the anions studied (sulfate, phosphate, GMP and ATP) strongly hinder vitamin release (C(anion)=1 x 10(-2) mol dm(-3)), whereas at pH 7 the delivery was observed for sulfate and GMP whereas the gate remained closed in the presence of ATP and phosphate. Selective delivery at neutral pH and no-liberation in acidic conditions can also be controlled with ATP and GMP using a suitable concentration of anion. The remarkable anion-controllable response of the gate-like ensemble at a certain pH can be explained in terms of anion complex formation with the tethered polyamines. Finally, selectivity patterns have been discussed in terms of kinetic rates of vitamin B(2) release. The pH-controlled gate-like scaffoldings on S1 might be a suitable prototype for the development of orally applicable delivery systems designed to have the particular ability to protect the cargo from the acidic conditions of the stomach (acid pH, gate closed) but will release the load at the intestine (basic pH, gate open).

Gastrointestinal complications in liver transplant recipients: MITOS study

INTRODUCTION

Liver transplant recipients frequently suffer gastrointestinal (GI) complications but their prevalence and their influence on quality of life remain unknown.

OBJECTIVE

The objective of this study was to asses the prevalence, impact on quality of life, and management of GI complications in liver transplant recipients.

PATIENTS AND METHODS

This was an epidemiologic, cross-sectional, multicenter study. Four hundred seventeen liver recipients were recruited in 14 centers. A questionnaire was filled for every patient.

RESULTS

The median age of the patients was 55 years. The median time since transplantation was 4.1 +/- 4 years. Whereas 19.2% presented some GI disease before transplantation, 49.4% showed this type of complication after transplantation. Diarrhea was the most prevalent GI complication, and anorexia was the GI disorder that affected patients daily activities the most frequently. GI complications were more frequent among female patients, subjects with pretransplantation hiatal hernia, and those readmitted after transplantation. Of the patients with GI complications, 70.9% received pharmacological treatment (89.7% with gastric protectors). Immunosuppressive therapy was also modified because of GI complications. Immunosuppressive drug dose was reduced in 18.1%, transiently stopped in 3.4%, and definitively stopped in 3.4% of cases. The drug most frequently changed was mycophenolate mofetil: dose reduction, 23.6%; transient withdrawal, 5.7%; and definitive withdrawal, 6.6%.

CONCLUSIONS

The prevalence of GI complications in the liver transplant population was approximately 50%. GI complications showed a significant impact on the quality of life of the patients. They were related to female gender, to pretransplantation GI pathology, and posttransplantation hospital admission. These complications were frequently managed with pharmacological therapy or with changes in immunosuppressive therapy.

Cancers of new appearance in liver transplant recipients: incidence and evolution

OBJECTIVE

To investigate the incidence, time of appearance, treatment, and evolution of tumors appearing in liver transplant recipients at our hospital.

MATERIAL AND METHODS

We undertook a retrospective analysis of our series of liver transplants between 1990 and 2005. Patients who died during the immediate postoperative period were excluded.

RESULTS

Of the 515 patients, 25 died during the immediate postoperative period and therefore had no occasion to develop neoplasms. Of the remaining 490, 32 developed cancers (6.5%). The average age was 55.4 +/- 7.17 years. The reasons for transplant were alcoholic cirrhosis (n = 15), hepatitis C virus (2), hepatitis B virus (n = 1), alcoholic and viral cirrhosis (n = 7), primary biliary cirrhosis (n = 1), and cryptogenic cirrhosis (n = 1). Four patients developed multiple neoplasms. Most of the tumors were cutaneous: nine basal cell and six squamous cell carcinomas. Other locations were the lung, urothelium, stomach, thyroid, and brain. Eight patients presented metastasis at the time of diagnosis. The average tumor-free period was 3.36 years. Nine patients died as a result of the tumor.

DISCUSSION

Patients with a liver transplant have a high risk of developing cancers as a result of the immunosuppression treatment, which is lifelong. Nevertheless, other factors can be involved, such as infection by cytomegalovirus or the original diagnosis leading to transplantation. The risk for developing cancers is significantly greater than in the general population, with a higher tendency to recurrence and later development of second neoplasms.

Morbidity and mortality in liver retransplantation

INTRODUCTION

The incidence of orthotopic liver retransplantation (re-OLT) ranges from 6% to 11%. The most frequent causes of early re-OLT are allograft failure, uncontrolled acute rejection, and vascular complications.

MATERIALS AND METHODS

A retrospective study of 512 orthotopic liver transplants (OLTs) in 482 patients over 15 years.

RESULTS

The incidence of re-OLT was 6.6%, with a higher percentage of men requiring re-OLT than first-time OLT (75.0% vs 63.0%, P < .05). The reasons for re-OLT were thrombosis 21.7%, aneurysm 6.5%, stenosis 3.2%, primary nonfunction (PNF) 21.7%, and chronic rejection or recurrence of the initial disease 40.4%. Complications included PNF (22.0%), acute renal failure (65.6%), postoperative infection (87.5%), and adult respiratory distress syndrome (9.4%; P < .05). No differences were seen in the incidence of septicemia or postoperative hemorrhage. The average survival was much lower in re-OLT (21.8 days) compared with OLT (194.5 days; P < .05). The mortality rates in re-OLT were 100% for primary biliary cirrhosis, 85.7% for HCV, 50% for alcoholic cirrhosis, and 20% for HBV. A direct association between the Model for End-stage Liver Disease (MELD) score and the number of complications was present.

DISCUSSION

There was a greater requirement for re-OLT in men and those patients transplanted due to hepatitis B virus cirrhosis and fulminant hepatitis (P < .05). The re-OLT patients had no greater incidence of sepsis compared with the OLT patients, although they did have a greater incidence of primary graft dysfunction, acute renal failure, adult respiratory distress syndrome, and postoperative infection (P < .05). The MELD was a good parameter for predicting graft evolution. Re-OLT in patients with primary biliary cirrhosis and hepatitis C virus was associated with a high degree of mortality.

Early postoperative response of cytokines in liver transplant recipients

We evaluated the early postoperative response of several cytokines (IL-2, IL-4, IL-6, IL-10, TNF-alpha, IFN-gamma) prior to liver transplantation (T(0)) as well as 1, 6, and 12 hours and 1, 2, 3, 5, and 7 days afterward. Cytokine concentrations were correlated with serum levels of bilirubin as a predictor of postoperative complications. Cytokine levels were determined in plasma samples from 16 liver transplant recipients (13 men, 3 women) aged 43 to 61 years. IL-6 and IL-10 reached their maximum concentrations 1 hour after transplantation. Each increase in IL-6 correlated to a rise in IL-10. IL-2, IL-4, TNF-alpha, and IFN-gamma had a particular time-course for each patient studied. Bilirubin fell to almost normal values but not in cases of postoperative complications, where IL-6 showed values four times higher compared to those of liver transplant recipients who did not show postoperative complications. IL-6 and IL-10 plasma concentrations and serum bilirubin level might be useful as a predictive factor of postoperative complications in liver transplant recipients.

Correlation Between the Radiologic and Histologic Size of Hepatocellular Carcinoma in Patients Eligible for Liver Transplantation

Hepatocellular carcinoma is the most prevalent primary hepatic tumor. Early diagnosis and staging is of paramount importance to obtain favorable survivals. So far, there is no general agreement on the most appropriate imaging technique to detect the tumor for correlation between pretransplant radiologic and pathologic size of the tumor, which remains inadequate. With greater clinical experience and increasing accuracy of imaging methods, magnetic resonance (MR) appears to be the most accurate method, yielding a correlation in 67% of cases.

Glutathione S-transferase T1 genetic mismatch is a risk factor for de novo immune hepatitis in liver transplantation

Glutathione S-transferase T1 (GSTT1) is a drug metabolizing enzyme abundantly expressed in liver and kidney cells; it is encoded by a single gene that is absent in 20% of the Caucasian population. Our group found that some liver transplantation patients developed de novo immune hepatitis (IH) and that all of them had anti-GSTT1 antibodies. The main objective of this study was to analyze the influence of a GSTT1 mismatch between donor and recipient in the immune response and the outcome of the graft. We confirmed that only under one of the four possible genetic combinations (null recipient/positive donor) is an alloimmune response triggered with production of anti-GSTT1 antibodies. Therefore, we conclude that this genetic mismatch can be considered a risk factor for de novo IH.