Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21
Filter
1.
Biotechnol Prog ; 40(1): e3393, 2024.
Article in English | MEDLINE | ID: mdl-37792408

ABSTRACT

Coffee is a crop of significant socioeconomic importance, and the reuse of agri-food by-products and biowaste has great potential across several industries. Coffee wastewater (CWW) is a valuable resource containing essential nutrients that can be utilized by Candida sorboxylosa for single-cell protein (SCP) production. This utilization contributes to mitigating the negative impacts of agro-industrial waste. The optimization of culture conditions using the design of experiments (DoE) technique is crucial in understanding the environmental factors influencing metabolite production. In our study, the DoE technique was employed to analyze culture conditions, including room temperature, pH 8.4, agitation at 200 rpm, a headspace of 60% (v/v), and an inoculum of 0.75 DO600nm over 28-h period. This approach resulted in a remarkable SCP yield of 64.4% and dry cell weight (DCW) of 2.26 g/L. It is noteworthy that there is no literature reporting SCP production under alkaline pH conditions in yeast. Interestingly, our work demonstrated that an alkaline pH of 8.4 significantly influenced SCP production by C. sorboxylosa. The DoE technique proved to be an efficient statistical tool for optimizing culture conditions, offering several advantages, such as: (i) conducting cultures at room temperature to minimize unnecessary energy consumption; (ii) reducing the incubation time from 46 to 28 h, thereby enhancing overall productivity; (iii) achieving 1.7-fold increase in SCP yield compared to previous basal production levels.


Subject(s)
Candida , Coffea , Wastewater , Coffee , Saccharomyces cerevisiae
2.
J Funct Biomater ; 14(9)2023 Sep 18.
Article in English | MEDLINE | ID: mdl-37754891

ABSTRACT

Breast cancer is a leading cause of cancer-related mortality among women worldwide, with millions of new cases diagnosed yearly. Addressing the burden of breast cancer mortality requires a comprehensive approach involving early detection, accurate diagnosis, effective treatment, and equitable access to healthcare services. In this direction, nano-radiopharmaceuticals have shown potential for enhancing breast cancer diagnosis by combining the benefits of nanoparticles and radiopharmaceutical agents. These nanoscale formulations can provide improved imaging capabilities, increased targeting specificity, and enhanced sensitivity for detecting breast cancer lesions. In this study, we developed and evaluated a novel nano-radio radiopharmaceutical, technetium-99m ([99mTc]Tc)-labeled trastuzumab (TRZ)-decorated methotrexate (MTX)-loaded human serum albumin (HSA) nanoparticles ([99mTc]-TRZ-MTX-HSA), for the diagnosis of breast cancer. In this context, HSA and MTX-HSA nanoparticles were prepared. Conjugation of MTX-HSA nanoparticles with TRZ was performed using adsorption and covalent bonding methods. The prepared formulations were evaluated for particle size, PDI value, zeta (ζ) potential, scanning electron microscopy analysis, encapsulation efficiency, and loading capacity and cytotoxicity on MCF-7, 4T1, and MCF-10A cells. Finally, the nanoparticles were radiolabeled with [99mTc]Tc using the direct radiolabeling method, and cellular uptake was performed with the nano-radiopharmaceutical. The results showed the formation of spherical nanoparticles, with a particle size of 224.1 ± 2.46 nm, a PDI value of 0.09 ± 0.07, and a ζ potential value of -16.4 ± 0.53 mV. The encapsulation efficiency of MTX was found to be 32.46 ± 1.12%, and the amount of TRZ was 80.26 ± 1.96%. The labeling with [99mTc]Tc showed a high labeling efficiency (>99%). The cytotoxicity studies showed no effect, and the cellular uptake studies showed 97.54 ± 2.16% uptake in MCF-7 cells at the 120th min and were found to have a 3-fold higher uptake in cancer cells than in healthy cells. In conclusion, [99mTc]Tc-TRZ-MTX-HSA nanoparticles are promising for diagnosing breast cancer and evaluating the response to treatment in breast cancer patients.

3.
ACS Appl Mater Interfaces ; 15(22): 26496-26509, 2023 Jun 07.
Article in English | MEDLINE | ID: mdl-37219485

ABSTRACT

Curcumin (CUR) is one natural bioactive compound acknowledged for diverse therapeutic activities, but its use is hindered by its poor bioavailability, fast metabolism, and susceptibility to pH variations and light exposure. Thus, the encapsulation in poly(lactic-co-glycolic acid), or PLGA, has been successfully used to protect and enhance CUR absorption in the organism, making CUR-loaded PLGA nanoparticles (NPs) promising drug delivery systems. However, few studies have focused beyond CUR bioavailability, on the environmental variables involved in the encapsulation process, and whether they could help obtain NPs of superior performance. Our study evaluated pH (3.0 or 7.0), temperature (15 or 35 °C), light exposure, and inert atmosphere (N2) incidence in the encapsulation of CUR. The best outcome was at pH 3.0, 15 °C, without light incidence, and without N2 usage. This best nanoformulation showed NP size, zeta potential, and encapsulation efficiency (EE) of 297 nm, -21 mV, and 72%, respectively. Moreover, the CUR in vitro release at pH values 5.5 and 7.4 suggested different potential applications for these NPs, one of which was demonstrated by the effective inhibition of multiple bacteria (i.e., Gram-negative, Gram-positive, and multi-resistant) in the minimal inhibition concentration assay. Besides, statistical analyses confirmed a significant impact of temperature on the NP size; in addition, temperature, light, and N2 affected the EE of CUR. Thus, the selection and control of process variables resulted in higher CUR encapsulation and customizable outcomes, ultimately enabling more economical processes and providing future scale-up guidelines.


Subject(s)
Curcumin , Nanoparticles , Curcumin/pharmacology , Curcumin/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Glycols , Drug Delivery Systems , Nanoparticles/chemistry , Particle Size , Drug Carriers/chemistry
4.
Molecules ; 28(4)2023 Feb 16.
Article in English | MEDLINE | ID: mdl-36838849

ABSTRACT

Many plants are used by the population through popular knowledge passed from generation to generation for the treatment of various diseases. However, there is not always any scientific content supporting these uses, which is very important for safety. One of these plants is the fruit of the Spondias genus, which during its processing generates various residues that are discarded, but which also have pharmacological properties. The focus of this review is to survey the pharmacological activities that Spondias genus shows, as well as which part of the plant is used, since there is a lot of richness in its by-products, such as leaf, bark, resin, seed, and peel, which are discarded and could be reused. The main activities of this genus are antioxidant, anti-inflammatory, antidiabetic, antifungal, and antiviral, among others. These properties indicate that this genus could be used in the treatment of several diseases, but there are still not many products available on the market that use this genus as an active ingredient.


Subject(s)
Anacardiaceae , Plant Extracts , Ethnopharmacology , Plant Extracts/chemistry , Phytotherapy , Medicine, Traditional , Phytochemicals
5.
Molecules ; 28(3)2023 Feb 02.
Article in English | MEDLINE | ID: mdl-36771111

ABSTRACT

Achieving the best possible outcome for the therapy is the main goal of a medicine. Therefore, nanocarriers and co-delivery strategies were invented to meet this need, as they can benefit many diseases. This approach was applied specifically for cancer treatment, with some success. However, these strategies may benefit many other clinical issues. Skin is the largest and most exposed organ of the human body, with physiological and psychological properties. Due to its exposition and importance, it is not difficult to understand how many skin diseases may impact on patients' lives, representing an important burden for society. Thus, this review aims to summarize the state of the art in research concerning nanocarriers and co-delivery strategies for topical agents' applications targeting skin diseases. The challenge for the medicine of the future is to deliver the drug with spatial and temporal control. Therefore, the co-encapsulation of drugs and the appropriate form of administration for them are so important and remain as unmet needs.


Subject(s)
Nanoparticles , Skin Diseases , Humans , Pharmaceutical Preparations/metabolism , Skin/metabolism , Skin Absorption , Skin Diseases/metabolism , Drug Delivery Systems , Drug Carriers/metabolism , Administration, Cutaneous , Administration, Topical
6.
J Control Release ; 353: 802-822, 2023 01.
Article in English | MEDLINE | ID: mdl-36521691

ABSTRACT

This paper provides a review of the literature on the use of Pluronic® triblock copolymers for drug encapsulation over the last 10 years. A special focus is given to the progress of drug delivery systems (e.g., micelles, liposomes, micro/nanoemulsions, hydrogels and nanogels, and polymersomes and niosomes); the beneficial aspects of Pluronic® triblock copolymers as biological response modifiers and as pharmaceutical additives, adjuvants, and stabilizers, are also discussed. The advantages and limitations encountered in developing site-specific targeting approaches based on Pluronic-based nanostructures in cancer treatment are highlighted, in addition to innovative examples for improving tumor cytotoxicity while reducing side effects.


Subject(s)
Neoplasms , Poloxamer , Humans , Poloxamer/chemistry , Polymers/chemistry , Drug Delivery Systems , Micelles , Neoplasms/drug therapy
7.
Colloids Surf B Biointerfaces ; 222: 113043, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36455361

ABSTRACT

Nanocarriers can deliver drugs to specific organs or cells, potentially bridging the gap between a drug's function and its interaction with biological systems such as human physiology. The untapped potential of nanotechnology stems from its ability to manipulate materials, allowing control over physical and chemical properties and overcoming drug-related problems, e.g., poor solubility or poor bioavailability. For example, most protein drugs are administered parenterally, each with challenges and peculiarities. Some problems faced by bioengineered macromolecule drugs leading to poor bioavailability are short biological half-life, large size and high molecular weight, low permeability through biological membranes, and structural instability. Nanotechnology emerges as a promising strategy to overcome these problems. Nevertheless, the delivery system should be carefully chosen considering loading efficiency, physicochemical properties, production conditions, toxicity, and regulations. Moving from the bench to the bedside is still one of the major bottlenecks in nanomedicine, and toxicological issues are the greatest challenges to overcome. This review provides an overview of biotech drug delivery approaches, associated nanotechnology novelty, toxicological issues, and regulations.


Subject(s)
Nanoparticles , Nanotechnology , Humans , Drug Delivery Systems , Nanomedicine , Pharmaceutical Preparations/chemistry , Proteins , Macromolecular Substances , Nanoparticles/chemistry
8.
Polymers (Basel) ; 14(17)2022 Aug 26.
Article in English | MEDLINE | ID: mdl-36080572

ABSTRACT

Based on the previous study, in which nisin and bacterial cellulose were utilized, this new experiment loads nisin into bacterial cellulose (N-BC) and evaluates the morphological characteristics, cytotoxicity, antimicrobial activity and stability of the developed system. The load efficiency of nisin in BC was evaluated by an agar diffusion assay, utilizing Lactobacillus sakei, and total proteins. After having found the ideal time and concentration for the loading process, the system stability was evaluated for 100 days at 4, 25 and 37 °C against Staphylococcus aureus and L. sakei. Thus, in this study, there is a system that proves to be efficient, once BC has enhanced the antimicrobial activity of nisin, acting as a selective barrier for other compounds present in the standard solution and protecting the peptide. After 4 h, with 45% of proteins, this activity was almost 2 log10 higher than that of the initial solution. Once the nisin solution was not pure, it is possible to suggest that the BC may have acted as a filter. This barrier enhanced the nisin activity and, as a consequence of the nisin loading, a stable N-BC system formed. The N-BC could create meaningful material for pharmaceutical and food applications.

9.
Environ Monit Assess ; 193(5): 285, 2021 Apr 20.
Article in English | MEDLINE | ID: mdl-33876320

ABSTRACT

Safeguarding the environment is one of the most serious modern challenges, as increasing amounts of chemical compounds are produced and released into the environment, causing a serious threat to the future health of the Earth as well as organisms and humans on a global scale. Ecotoxicology is an integrative science involving different physical, chemical, biological, and social aspects concerned with the study of toxic effects caused by natural or synthetic pollutants on any constituents of ecosystems, including animals (including humans), plants, or microorganisms, in an integral context. In recent decades, this science has undergone considerable development by addressing environmental risk assessments through the biomonitoring of indicator species using biomarkers, model organisms, and nanocompounds in toxicological assays. Since a single taxon cannot be representative of complex ecotoxicological effects and mechanisms of action of a chemical, the use of test batteries is widely accepted in ecotoxicology. Test batteries include properly chosen organisms that are easy to breed, adapt easily to laboratory conditions, and are representative of the environmental compartment under consideration. One of the main issues of toxicological and ecotoxicological research is to gain a deeper understanding of how data should be obtained through laboratory and field approaches using experimental models and how they could be extrapolated to humans. There is a tendency to replace animal tests with in vitro systems and to perform them according to standardized analytical methods and the rules of the so-called good laboratory practice (GLP). This paper aims to review this topic to stimulate both efforts to understand the toxicological and ecotoxicological properties of natural and synthetic chemicals and the possible use of such data for application to humans.


Subject(s)
Environmental Monitoring , Water Pollutants, Chemical , Animals , Biological Assay , Ecosystem , Ecotoxicology , Humans , Risk Assessment , Water Pollutants, Chemical/analysis
10.
J Fungi (Basel) ; 6(4)2020 Nov 02.
Article in English | MEDLINE | ID: mdl-33147713

ABSTRACT

Natural colorants from microbial fermentation have gained significant attention in the market to replace the synthetic ones. Talaromyces spp. produce yellow-orange-red colorants, appearing as a potential microorganism to be used for this purpose. In this work, the production of natural colorants by T. amestolkiae in a stirred-tank bioreactor is studied, followed by its application as additives in bio-based films. The effect of the pH-shift control strategy from 4.5 to 8.0 after 96 h of cultivation is evaluated at 500 rpm, resulting in an improvement of natural colorant production, with this increase being more significant for the orange and red ones, both close to 4-fold. Next, the fermented broth containing the colorants is applied to the preparation of cassava starch-based films in order to incorporate functional activity in biodegradable films for food packaging. The presence of fermented broth did not affect the water activity and total solids of biodegradable films as compared with the standard one. In the end, the films are used to pack butter samples (for 45 days) showing excellent results regarding antioxidant activity. It is demonstrated that the presence of natural colorants is obtained by a biotechnology process, which can provide protection against oxidative action, as well as be a functional food additive in food packing biomaterials.

11.
Biotechnol Appl Biochem ; 65(3): 381-389, 2018 May.
Article in English | MEDLINE | ID: mdl-29205941

ABSTRACT

Viral vectors are important in medical approaches, such as disease prevention and gene therapy, and their production depends on efficient prepurification steps. In the present study, an aqueous two-phase micellar system (ATPMS) was evaluated to extract human adenovirus type 5 particles from a cell lysate. Adenovirus was cultured in human embryonic kidney 293 (HEK-293) cells to a concentration of 1.4 × 1010 particles/mL. Cells were lysed, and the system formed by direct addition of Triton X-114 in a 23 full factorial design with center points. The systems were formed with Triton X-114 at a final concentration of 1.0, 6.0, and 11.0% (w/w), cell lysate pH of 6.0, 6.5, and 7.0, and incubation temperatures at 33, 35, and 37 °C. Adenovirus particles recovered from partition phases were measured by qPCR. The best system condition was with 11.0% (w/w) of Triton X-114, a cell lysate pH of 7.0, and an incubation temperature at 33 °C, yielding 3.51 × 1010 adenovirus particles/mL, which increased the initial adenovirus particles concentration by 2.3-fold, purifying it by 2.2-fold from the cell lysate, and removing cell debris. In conclusion, these results demonstrated that the use of an aqueous two-phase micellar system in the early steps of downstream processing could improve viral particle extraction from cultured cells while integrating clarification, concentration, and prepurification steps.


Subject(s)
Adenoviridae/isolation & purification , Cell Extracts/chemistry , Micelles , Water/chemistry , Cells, Cultured , Genetic Vectors/isolation & purification , HEK293 Cells , Humans
12.
Biotechnol Appl Biochem ; 65(3): 381-389, 2018. ilus, tab
Article in English | Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1060882

ABSTRACT

Viral vectors are important in medical approaches, such as disease prevention and gene therapy, and their production depends on efficient prepurification steps. In the present study, an aqueous two-phase micellar system (ATPMS) was evaluated to extract human adenovirus type 5 particles from a cell lysate. Adenovirus was cultured in human embryonic kidney 293 (HEK-293) cells to a concentration of 1.4 × 1010 particles/mL. Cells were lysed, and the system formed by direct addition of Triton X-114 in a 23 full factorial design with center points. The systems were formed with Triton X-114 at a final concentration of 1.0, 6.0, and 11.0% (w/w), cell lysate pH of 6.0, 6.5, and 7.0, and incubation temperatures at 33, 35, and 37 °C. Adenovirus particles recovered from partition phases were measured by qPCR. The best system condition was with 11.0% (w/w) of Triton X-114, a cell lysate pH of 7.0, and an incubation temperature at 33 °C, yielding 3.51 × 1010 adenovirus particles/mL, which increased the initial adenovirus particles concentration by 2.3-fold, purifying it by 2.2-fold from the cell lysate, and removing cell debris. In conclusion, these results demonstrated that the use of an aqueous two-phase micellar system in the early steps of downstream processing could improve viral particle extraction from cultured cells while integrating clarification, concentration, and prepurification steps.


Subject(s)
Humans , Genetic Vectors/isolation & purification , Water/chemistry
13.
Crit Rev Biotechnol ; 37(1): 82-99, 2017 Feb.
Article in English | MEDLINE | ID: mdl-26694875

ABSTRACT

l-asparaginase (l-asparagine amino hydrolase, E.C.3.5.1.1) is an enzyme clinically accepted as an antitumor agent to treat acute lymphoblastic leukemia and lymphosarcoma. It catalyzes l-asparagine (Asn) hydrolysis to l-aspartate and ammonia, and Asn effective depletion results in cytotoxicity to leukemic cells. Microbial l-asparaginase (ASNase) production has attracted considerable attention owing to its cost effectiveness and eco-friendliness. The focus of this review is to provide a thorough review on microbial ASNase production, with special emphasis to microbial producers, conditions of enzyme production, protein engineering, downstream processes, biochemical characteristics, enzyme stability, bioavailability, toxicity and allergy potential. Some issues are also highlighted that will have to be addressed to achieve better therapeutic results and less side effects of ASNase use in cancer treatment: (a) search for new sources of this enzyme to increase its availability as a drug; (b) production of new ASNases with improved pharmacodynamics, pharmacokinetics and toxicological profiles, and (c) improvement of ASNase production by recombinant microorganisms. In this regard, rational protein engineering, directed mutagenesis, metabolic flux analysis and optimization of purification protocols are expected to play a paramount role in the near future.


Subject(s)
Antineoplastic Agents , Asparaginase , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/therapeutic use , Asparaginase/chemistry , Asparaginase/metabolism , Asparaginase/therapeutic use , Bacteria/metabolism , Drug Compounding , Fungi/metabolism , Protein Engineering
14.
Appl Microbiol Biotechnol ; 100(5): 2063-72, 2016 03.
Article in English | MEDLINE | ID: mdl-26743657

ABSTRACT

Production of bacterial nanocellulose (BNC) is becoming increasingly popular owing to its environmentally friendly properties. Based on this benefit of BNC production, researchers have also begun to examine the capacity for cellulose production through microbial hosts. Indeed, several research groups have developed processes for BNC production, and many studies have been published to date, with the goal of developing methods for large-scale production. During BNC bioproduction, the culture medium represents approximately 30 % of the total cost. Therefore, one important and challenging aspect of the fermentation process is identification of a new cost-effective culture medium that can facilitate the production of high yields within short periods of time, thereby improving BNC production and permitting application of BNC in the biotechnological, medical, pharmaceutical, and food industries. In this review, we addressed different aspects of BNC production, including types of fermentation processes and culture media, with the aim of demonstrating the importance of these parameters.


Subject(s)
Bacteria/metabolism , Biotechnology/methods , Cellulose/metabolism , Biotechnology/economics , Culture Media/chemistry , Culture Media/economics , Fermentation
15.
Biomater Sci ; 4(2): 205-18, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26580477

ABSTRACT

Use of nanoscale devices as carriers for drugs and imaging agents has been extensively investigated and successful examples can already be found in therapy. In parallel, recombinant DNA technology together with molecular biology has opened up numerous possibilities for the large-scale production of many proteins of pharmaceutical interest, reflecting in the exponentially growing number of drugs of biotechnological origin. When we consider protein drugs, however, there are specific criteria to take into account to select adequate nanostructured systems as drug carriers. In this review, we highlight the main features, advantages, drawbacks and recent developments of nanostructures for protein encapsulation, such as nanoemulsions, liposomes, polymersomes, single-protein nanocapsules and hydrogel nanoparticles. We also discuss the importance of nanoparticle stabilization, as well as future opportunities and challenges in nanostructures for protein drug delivery.


Subject(s)
Drug Carriers/chemistry , Nanocapsules/chemistry , Nanoparticles/chemistry , Nanostructures/chemistry , Proteins/chemistry , Drug Delivery Systems , Humans , Liposomes , Proteins/metabolism
16.
Biotechnol Prog ; 32(1): 5-13, 2016.
Article in English | MEDLINE | ID: mdl-26518672

ABSTRACT

Bromelain is a cysteine protease found in pineapple tissue. Because of its anti-inflammatory and anti-cancer activities, as well as its ability to induce apoptotic cell death, bromelain has proved useful in several therapeutic areas. The market for this protease is growing, and several studies exploring various properties of this molecule have been reported. This review aims to compile this data, and summarize the main findings on bromelain in the literature to date. The physicochemical properties and stability of bromelain under different conditions are discussed. Several studies on the purification of bromelain from crude extracts using a wide range of techniques such as liquid-liquid extractions by aqueous two-phase system, ultrafiltration, precipitation, and chromatography, have been reported. Finally, the various applications of bromelain are presented. This review therefore covers the main properties of bromelain, aiming to provide an up-to-date compilation of the data reported on this enzyme.


Subject(s)
Ananas/chemistry , Bromelains/chemistry , Cysteine Proteases/chemistry , Amino Acid Sequence/genetics , Apoptosis/drug effects , Bromelains/genetics , Bromelains/isolation & purification , Bromelains/therapeutic use , Cysteine Proteases/therapeutic use , Humans
17.
Biotechnol Prog ; 31(5): 1295-304, 2015.
Article in English | MEDLINE | ID: mdl-26097197

ABSTRACT

Safety concerns related to the increasing and widespread application of synthetic coloring agents have increased the demand for natural colorants. Fungi have been employed in the production of novel and safer colorants. In order to obtain the colorants from fermented broth, suitable extraction systems must be developed. Aqueous two-phase polymer systems (ATPPS) offer a favorable chemical environment and provide a promising alternative for extracting and solubilizing these molecules. The aim of this study was to investigate the partitioning of red colorants from the fermented broth of Penicillium purpurogenum using an ATPPS composed of poly(ethylene glycol) (PEG) and sodium polyacrylate (NaPA). Red colorants partitioned preferentially to the top (PEG-rich phase). In systems composed of PEG 6,000 g/mol/NaPA 8,000 g/mol, optimum colorant partition coefficient (KC ) was obtained in the presence of NaCl 0.1 M (KC = 10.30) while the PEG 10,000 g/mol/NaPA 8,000 g/mol system in the presence of Na2 SO4 0.5 M showed the highest KC (14.78). For both polymers, the mass balance (%MB) and yield in the PEG phase (%ηTOP ) were close to 100 and 79%, respectively. The protein selectivity in all conditions evaluated ranged from 2.0-3.0, which shows a suitable separation of the red colorants and proteins present in the fermented broth. The results suggest that the partitioning of the red colorants is dependent on both the PEG molecular size and salt type. Furthermore, the results obtained support the potential application of ATPPS as the first step of a purification process to recover colorants from fermented broth of microorganisms.


Subject(s)
Coloring Agents/chemistry , Culture Media/chemistry , Fermentation , Penicillium/metabolism , Polymers/chemistry , Acrylic Resins/chemistry , Hydrogen-Ion Concentration , Molecular Weight , Polyethylene Glycols/chemistry , Proteins/chemistry , Salts/chemistry , Sodium Chloride/chemistry
18.
World J Microbiol Biotechnol ; 31(4): 649-59, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25677652

ABSTRACT

The use of poly(lactic-co-glycolic acid) (PLGA) matrix as a biomolecule carrier has been receiving great attention due to its potential therapeutic application. In this context, we investigated the PLGA matrix capacity to incorporate nisin, an antimicrobial peptide capable of inhibiting the growth of Gram-positive bacteria and bacterial spores germination. Nisin-incorporated PLGA matrices were evaluated based on the inhibitory effect against the nisin-bioindicator Lactobacillus sakei. Additionally, the PLGA-nisin matrix stability over an 8-months period was investigated, as well as the nisin release profile. For the incorporation conditions, we observed that a 5 h incorporation time, at 30 °C, with 250 µg/mL nisin solution in PBS buffer pH 4.5, resulted in the highest inhibitory activity of 2.70 logAU/mL. The PLGA-nisin matrix was found to be relatively stable and showed sustained drug delivery, with continuous release of nisin for 2 weeks. Therefore, PLGA-nisin matrix is could be used as a novel antimicrobial delivery system and an alternative to antibiotics incorporated into PLGA matrices.


Subject(s)
Anti-Bacterial Agents/chemistry , Drug Carriers/chemistry , Drug Delivery Systems/instrumentation , Lactic Acid/chemistry , Nisin/chemistry , Polyglycolic Acid/chemistry , Anti-Bacterial Agents/pharmacology , Lactobacillus/drug effects , Nanoparticles/chemistry , Nisin/pharmacology , Particle Size , Polylactic Acid-Polyglycolic Acid Copolymer
19.
Appl Microbiol Biotechnol ; 97(14): 6201-9, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23640365

ABSTRACT

Lipopolysaccharide endotoxins (LPS) are the most common pyrogenic substances in recombinant peptides and proteins purified from Gram-negative bacteria, such as Escherichia coli. In this respect, aqueous two-phase micellar systems (ATPMS) have already proven to be a good strategy to purify recombinant proteins of pharmaceutical interest and remove high LPS concentrations. In this paper, we review our recent experimental work in protein partitioning in Triton X-114 ATPMS altogether with some new results and show that LPS-protein aggregation can influence both protein and LPS partitioning. Green fluorescent protein (GFPuv) was employed as a model protein. The ATPMS technology proved to be effective for high loads of LPS removal into the micelle-rich phase (%REM(LPS) > 98 %) while GFPuv partitioned preferentially to the micelle-poor phase (K GFP(uv) < 1.00) due to the excluded-volume interactions. However, theoretically predicted protein partition coefficient values were compared with experimentally obtained ones, and good agreement was found only in the absence of LPS. Dynamic light scattering measurements showed that protein-LPS interactions were taking place and influenced the partitioning process. We believe that this phenomenon should be considered in LPS removal employing any kind of aqueous two-phase system. Nonetheless, ATPMS can still be considered as an efficient strategy for high loads of LPS removal, but being aware that the excluded-volume partitioning theory available might overestimate partition coefficient values due to the presence of protein-LPS aggregation.


Subject(s)
Green Fluorescent Proteins/chemistry , Lipopolysaccharides/chemistry , Escherichia coli/chemistry , Escherichia coli/genetics , Escherichia coli/metabolism , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/isolation & purification , Kinetics , Lipopolysaccharides/metabolism , Micelles , Protein Binding , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification
20.
Se Pu ; 30(11): 1194-202, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23451525

ABSTRACT

Endotoxins (also known as lipopolysaccharides (LPS)) are undesirable by-products of recombinant proteins, purified from Escherichia coli. LPS can be considered stable under a wide range of temperature and pH, making their removal one of the most difficult tasks in downstream processes during protein purification. The inherent toxicity of LPS makes their removal an important step for the application of these proteins in several biological assays and for a safe parenteral administration. Immobilized metal affinity chromatography (IMAC) enables the affinity interactions between the metal ions (immobilized on the support through the chelating compound) and the target molecules, thus enabling high-efficiency separation of the target molecules from other components present in a mixture. Affinity chromatography is applied with Ca2+ -iminodiacetic acid (IDA) to remove most of the LPS contaminants from the end product (more than 90%). In this study, the adsorption of LPS on an IDA-Ca2+ was investigated. The adsorption Freundlich isotherm of LPS-IDA-Ca2+ provides a theoretical basis for LPS removal. It was found that LPS is bound mainly by interactions between the phosphate group in LPS and Ca2+ ligands on the beads. The factors such as pH (4.0 or 5.5) and ionic strength (1.0 mol/L) are essential to obtain effective removal of LPS for contaminant levels between endotoxin' concentration values less than 100 EU/mL and 100 000 EU/mL. This new protocol represents a substantial advantage in time, effort, and production costs.


Subject(s)
Chromatography, Affinity/methods , Endotoxins/isolation & purification , Recombinant Proteins/chemistry , Adsorption , Calcium/chemistry , Escherichia coli , Imino Acids/chemistry , Ions/chemistry , Metals/chemistry , Proteins/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...