Fabrication of a Silk Sericin Hydrogel System Delivering Human Lactoferrin Using Genetically Engineered Silk with Improved Bioavailability to Alleviate Chemotherapy-Induced Immunosuppression.

Chemotherapy is one of the main treatments for cancer; however, it usually causes severe atrophy of immune organs and self-immunity damage to patients. Human lactoferrin (hLF) is a multiple biofunctional protein in regulating the immune response and thus holds great promise to alleviate chemotherapy-caused immunosuppression. However, a sufficient hLF resource and efficient delivery of hLF remain a challenge. Here, we provide a useful strategy to simultaneously solve these two problems. A silk sericin hydrogel system delivering recombinant hLF (SSH-rhLF) was fabricated to alleviate the chemotherapeutic drug-caused side effects by rhLF-carrying silk cocoons, which were cost-effectively produced by a transgenic silkworm strain as the resource. SSH-rhLF with a uniform porous microstructural morphology, a dominant ß-sheet internal structure, adjustable concentration and sustainable release of the rhLF, and non-cytotoxicity properties was demonstrated. Interestingly, the sericin hydrogel showed effective protection of the rhLF from degradation in the stomach and small intestine, thus prolonging the bioactivity and bioavailability of rhLF. As a result, the oral administration of SSH-rhLF with a low rhLF dose showed significant therapeutic effects on enhancing the immune organs of cyclophosphamide (CTX)-treated mice by protecting the splenic follicles, promoting the expression of immunoregulatory factors, and recovering the intestinal flora family from CTX-induced imbalance, which were similar to those achieved by oral administration of a high dose of free hLF in the solution form. The results suggest that the strategy of producing rhLF silk cocoons via feeding transgenic silkworms overcomes well the shortage of rhLF resources, improves the bioavailability of oral rhLF, and alleviates the side effects of chemotherapeutic drugs on immune organs. The oral SSH-rhLF will be promising for applications in cancer chemotherapy and immunity enhancement of patients.

Daily Dose of Bovine Lactoferrin Prevents Ethanol-Induced Liver Injury and Death in Male Mice by Regulating Hepatic Alcohol Metabolism and Modulating Gut Microbiota.

SCOPE: Lactoferrin (Lf) possess a protective potential to liver, but whether it can prevent alcoholic liver injury (ALI) remains unclear. METHODS AND RESULTS: Four groups of male C57BL/6J mice are fed with different diets, namely, AIN-93G diet for control (CON) and ethanol (EtOH) groups, and AIN-93G diet with 0.4% and 4% casein replaced by Lf for low-dose Lf (LLf) and high-dose Lf (HLf) groups, respectively. ALI is induced by giving 20% ethanol ad libitum combined with four "binges". Lf can remarkably decrease EtOH-induced mortality. Lf promotes aldehyde dehydrogenase-2 (ALDH2) expression and suppressing cytochrome P450 2E1 (CYP2E1) overexpression, resulting in the reduced hepatic superoxide and inflammation levels, which ultimately leads to the hepatic injury alleviation. However, HLf increases acetyl-CoA carboxylase and fatty acid synthase protein levels, which suggests that excessive intake may weaken the beneficial effects of Lf. Moreover, LLf increases the relative abundances of Akkermansia and Lactobacillus. Additionally, the study shows that Lf likely exerts action in its digestive product forms rather than intact Lf molecular in normal condition. CONCLUSION: LLf can ameliorate ALI, which is associated with the regulation of hepatic alcohol metabolism and the modulation of gut microbiota. However, excessive Lf intake may result in a diminished benefit.

The impact of thermal processing on the simulated infant gastrointestinal digestion, bactericidal and anti-inflammatory activity of bovine lactoferrin - An in vitro study.

Lactoferrin (LF) is a multifunctional glycoprotein which, when thermally processed, undergoes significant physicochemical changes. The link between such changes and the bioactivity of LF is not well characterised and requires much research. In this work, bovine LF solutions (1%, w/v, protein, pH 7) were thermally processed using high temperature short time conditions (72, 80, 85 or 95 °C with 15 s holding times). Following this, it was shown that LF and heat induced LF aggregates were largely resistant to simulated infant gastric, but not intestinal, digestion. Also, the efficacy of LF bactericidal activity, and inhibition of lipopolysaccharide-induced NF-κB activation were negatively impacted by thermal processing. This study confirmed that the efficacy of LF bio-functionalities was affected by the extent of heat-induced changes in protein structure whereby processing conditions of least severity (i.e. pasteurisation) had the least impact on bioactivity.

Design, Optimization, and Characterization of Lactoferrin-Loaded Chitosan/TPP and Chitosan/Sulfobutylether-ß-cyclodextrin Nanoparticles as a Pharmacological Alternative for Keratoconus Treatment.

This research study describes the design, optimization, and characterization of two different types of chitosan-based nanoparticles as novel drug delivery systems of a protein drug, lactoferrin. A preclinical consistent base was obtained for both nanosystems, being considered as the first pharmacological treatment for keratoconus as an alternative to current invasive clinical methods. Both types of nanoparticles were obtained via the ionotropic gelation technique. The size and morphology of the nanoparticles were studied as a function of the preparation conditions. A mean size of 180.73 ± 40.67 nm, a size distribution [polydispersity index (PDI)] of 0.170 ± 0.067, and positive ζ-potential values, ranging from 17.13 to 19.89 mV, were achieved. Lactoferrin was successfully incorporated into both types of nanocarriers. In vitro release profiles showed a lactoferrin enhanced, prolonged, and controlled delivery from the polymeric matrix. These formulations also demonstrated no stability or cytotoxicity problems, as well as appropriate mucoadhesive properties, with a high permanence time in the ocular surface. Thus, both types of nanoparticles may be considered as nanocarriers for the controlled release of lactoferrin as novel topical ophthalmic drug delivery systems.

Effect of milk serum proteins on aggregation, bacteriostatic activity and digestion of lactoferrin after heat treatment.

To establish the effect of the presence of milk serum proteins on heat-induced changes to lactoferrin, lactoferrin alone, and lactoferrin mixed with either milk serum or ß-lactoglobulin was heated at 65 °C, 70 °C and 75 °C for 30 min. After heating, the effect of milk serum proteins on aggregation of lactoferrin was characterized, after which the effect of such aggregation on digestion and bacteriostatic capacity of lactoferrin were determined. The presence of milk serum proteins accelerated the aggregation of lactoferrin during heating through thiol/disulphide interchange. Lactoferrin also formed disulphide-linked aggregates when it was heated with ß-lactoglobulin. Protein aggregates formed at 75 °C were much more resistant to infant digestion, causing decreased peptide release from lactoferrin. Heating lactoferrin and milk serum proteins together accelerated the loss of bacteriostatic activity upon heating. In conclusion, heat-induced aggregation of lactoferrin with milk serum proteins affected both its digestion and its bacteriostatic activity.

An in vitro digestion study of encapsulated lactoferrin in rapeseed phospholipid-based liposomes.

Effectiveness of liposomes elaborated with rapeseed phospholipid (RP) extracted from a residue of oil processing, stigmasterol (ST) and/or hydrogenated phosphatidylcholine (HPC) for the encapsulation lactoferrin (LF) was studied; lipid membrane of liposomes was characterized (bilayer size, chain conformational order, lateral packing, lipid phase, and morphology) and the protection offered to the encapsulated LF during in vitro digestion was determined. Liposomes composed of RP+STLC(low concentration) showed spherical and irregular vesicles without perforations. Lamellar structure was organized in a liquid-ordered phase with a potential orthorhombic packing. Stability and size of the liposomes were more affected by gastric digestion than intestinal digestion; 67-80% of the initially encapsulated LF remained intact after gastric digestion whereas the percentage was reduced to 16-35% after intestinal digestion. Our results shows that liposomes elaborated with RP, properly combined with other lipids, can be a useful oral delivery system of molecules sensitive to digestive enzymes.

Lactoferrin's Anti-Cancer Properties: Safety, Selectivity, and Wide Range of Action.

Despite recent advances in cancer therapy, current treatments, including radiotherapy, chemotherapy, and immunotherapy, although beneficial, present attendant side effects and long-term sequelae, usually more or less affecting quality of life of the patients. Indeed, except for most of the immunotherapeutic agents, the complete lack of selectivity between normal and cancer cells for radio- and chemotherapy can make them potential antagonists of the host anti-cancer self-defense over time. Recently, the use of nutraceuticals as natural compounds corroborating anti-cancer standard therapy is emerging as a promising tool for their relative abundance, bioavailability, safety, low-cost effectiveness, and immuno-compatibility with the host. In this review, we outlined the anti-cancer properties of Lactoferrin (Lf), an iron-binding glycoprotein of the innate immune defense. Lf shows high bioavailability after oral administration, high selectivity toward cancer cells, and a wide range of molecular targets controlling tumor proliferation, survival, migration, invasion, and metastasization. Of note, Lf is able to promote or inhibit cell proliferation and migration depending on whether it acts upon normal or cancerous cells, respectively. Importantly, Lf administration is highly tolerated and does not present significant adverse effects. Moreover, Lf can prevent development or inhibit cancer growth by boosting adaptive immune response. Finally, Lf was recently found to be an ideal carrier for chemotherapeutics, even for the treatment of brain tumors due to its ability to cross the blood-brain barrier, thus globally appearing as a promising tool for cancer prevention and treatment, especially in combination therapies.

The bovine Lactoferrin-Osteopontin complex increases proliferation of human intestinal epithelial cells by activating the PI3K/Akt signaling pathway.

Lactoferrin (LF) and osteopontin (OPN), multifunctional proteins involved in cell proliferation, can form a complex. LF binds iron, whereas OPN binds calcium. We investigated whether iron- and calcium-binding influences complex formation and the pro-proliferation property of the LF-OPN complex, and the mechanism behind this effect. LF-OPN complexes were prepared using bovine milk LF and OPN, and effects on proliferation of human intestinal epithelial cells (HIECs) were evaluated using a BrdU proliferation assay. Of the four complexes formed by apo- and holo-LF/OPN, the apo-Lf&holo-OPN complex (AH) exhibited the strongest pro-proliferative effect on HIECs, and we therefore focused on AH. AH was resistant to in vitro gastrointestinal digestion, co-localized with both LF and OPN receptors as revealed by confocal microscopy, and stimulated proliferation of HIECs by activating PI3K/Akt signaling. In conclusion, forming a LF-OPN complex may help both proteins to resist digestion and increase the capacity to promote intestinal development in infants.

Assessment of bioactivities of the human milk lactoferrin-osteopontin complex in vitro.

Lactoferrin (LF) and osteopontin (OPN) are both multi-functional whey proteins present at high levels in human milk. These two proteins have a high affinity for each other due to their opposite charges; LF is a basic glycoprotein while OPN is an acidic phosphorylated glycoprotein. LF and OPN were identified to bind to each other over a decade ago, but potential functions of their complex remain unexplored. In this work, we investigated the characteristics of the LF-OPN complex with a focus on its bioactivities. Our results reveal a stronger stability of the LF-OPN complex towards in vitro digestion and more effective binding and uptake by human intestinal cells (HIEC) than LF or OPN alone show. Moreover, the LF-OPN complex promotes proliferation and differentiation of intestinal cells significantly more than the individual proteins do and shows an effect on anti-bacterial function and immune-stimulatory activities intermediate between those of LF and OPN. Thus, by forming a complex in human milk, LF and OPN may protect each other against proteolysis and enhance their individual bioactivities.

Very Short and Stable Lactoferricin-Derived Antimicrobial Peptides: Design Principles and Potential Uses.

The alarming rate at which micro-organisms are developing resistance to conventional antibiotics represents one of the global challenges of our time. There is currently ample space in the antibacterial drug pipeline, and scientists are trying to find innovative and novel strategies to target the microbial enemies. Nature has remained a source of inspiration for most of the antibiotics developed and used, and the immune molecules produced by the innate defense systems, as a first line of defense, have been heralded as the next source of antibiotics. Most living organisms produce an arsenal of antimicrobial peptides (AMPs) to rapidly fend off intruding pathogens, and several different attempts have been made to transform this versatile group of compounds into the next generation of antibiotics. However, faced with the many hurdles of using peptides as drugs, the success of these defense molecules as therapeutics remains to be realized. AMPs derived from the proteolytic degradation of the innate defense protein lactoferrin have been shown to display several favorable antimicrobial properties. In an attempt to investigate the biological and pharmacological properties of these much shorter AMPs, the sequence dependence was investigated, and it was shown, through a series of truncation experiments, that these AMPs in fact can be prepared as tripeptides, with improved antimicrobial activity, via the incorporation of unnatural hydrophobic residues and terminal cappings. In this Account, we describe how this class of promising cationic tripeptides has been developed to specifically address the main challenges limiting the general use of AMPs. This has been made possible through the identification of the antibacterial pharmacophore and via the incorporation of a range of unnatural hydrophobic and cationic amino acids. Incorporation of these residues at selected positions has allowed us to extensively establish how these compounds interact with the major proteolytic enzymes trypsin and chymotrypsin and also the two major drug-binding plasma proteins serum albumin and α-1 glycoprotein. Several of the challenges associated with using AMPs relate to their size, susceptibility to rapid proteolytic degradation, and poor oral bioavailability. Our studies have addressed these issues in detail, and the results have allowed us to effectively design and prepare active and metabolically stable AMPs that have been evaluated in a range of functional settings. The optimized short AMPs display inhibitory activities against a plethora of micro-organisms at low micromolar concentrations, and they have been shown to target resistant strains of both bacteria and fungi alike with a very rapid mode of action. Our Account further describes how these compounds behave in in vivo experiments and highlights both the challenges and possibilities of the intriguing compounds. In several areas, they have been shown to exhibit comparable or superior activity to established antibacterial, antifungal, and antifouling commercial products. This illustrates their ability to effectively target and eradicate various microbes in a variety of settings ranging from the ocean to the clinic.

Lactoferrin and lactoferricin endocytosis halt Giardia cell growth and prevent infective cyst production.

Lactoferrin (LF) is an 80 KDa iron-binding glycoprotein that plays a significant role in the innate immune system and is considered to be an important microbicide molecule. It has been suggested to be effective in the treatment of giardiasis, an intestinal disease caused by the protozoan parasite G. lamblia. However, the molecular mechanisms by which LF exerts its effect on this parasite are unknown. Most of the microbicidal activity of human or bovine LF (hLF or bLF) has been associated with the N-terminal region of the mature LF - lactoferricin (LFcin). LFcin is produced by pepsin cleavage of the native protein in vitro and likely in vivo. In this work, we analyse the participation of the endocytic machinery of G. lamblia in the internalization of bLF and bLFcin and their effects on cell homeostasis. Our results show that, when bLF or bLFcin are internalized by receptor-mediated endocytosis, cell growth stops, and morphological changes are produced in the trophozoites, which ultimately will produce immature cysts. Our findings contribute to disclose the fine mechanism by which bLF and bLFcin may function as an antigiardial molecule and why they have therapeutic potential to eradicate giardiasis.

Bioavailability of a Novel Form of Microencapsulated Bovine Lactoferrin and Its Effect on Inflammatory Markers and the Gut Microbiome: A Pilot Study.

Bovine lactoferrin, extracted from milk or whey, is used in a range of products to enhance immunity and support digestive health, iron absorption, and homeostasis. This study examined the absorption and effect of Progel (Brisbane, Queensland, Australia) microencapsulated bovine lactoferrin (InferrinTM, Bega Bionutrients, Victoria, Australia) on immune markers and the microbiome. A double-blind randomised, cross-over trial was conducted with 12 healthy males randomised to one of two doses, equivalent to 200 mg or 600 mg lactoferrin, for two four-week supplementation arms, with a two-week washout period. Subjects received either standard bovine lactoferrin or InferrinTM for each arm. Baseline and post each trial arm, CD69+ activation on CD4+ and CD8+ cells was analysed, bovine and human lactoferrin contents of faecal and serum samples were reported, and the gut microbiome was analysed using 16S sequencing and metagenomic sequencing. The mean level of CD69+ activation on the CD4+ cells was lower after supplementation regardless of the form or dose of lactoferrin. This was statistically significant for the 200 mg dose. A higher level of bovine lactoferrin was found post-supplementation in those taking InferrinTM, although this was not statistically significant. Changes in phylum-level microbial community profiling were detected post-supplementation in the second trial arm, particularly in those receiving InferrinTM. Metagenomic sequencing showed changes in the volumes of the top 100 species of bacteria present before and after all treatment arms. Results suggest that lactoferrin supplementation may have beneficial effects on the microbiome and immune system, and that the use of InferrinTM improves absorption. Larger detailed studies are needed to ascertain the potential positive effects of bovine lactoferrin supplementation.

Comparative performances of lactoferrin-loaded liposomes under in vitro adult and infant digestion models.

There remain gaps in our understanding of the fate of liposomes in the infant gastrointestinal tract, especially regarding essential proteins such as lactoferrin. Models in vitro that mirrored digestion in the stomach and intestine of infants and adults were used to explore the behaviour of lactoferrin-loaded liposomes. The liposomes behaved differently in these environments, with less hydrolysis of encapsulated lactoferrin under infant model conditions. Compared to the adult model (1000 ±â€¯66 µM mL-1), fewer free fatty acids were released (500 ±â€¯43 µM mL-1) from liposomal bilayers and there was less alteration in functional groups of phospholipids membranes, based on pH and FTIR after infant model digestion. Particle tracking analysis and TEM supported the reduced damage of particle structure under infant model conditions. This work provides information on the stability of functional protein-loaded liposomes during digestion, and shows the potential of liposomes to be nutrient carriers in infant foods.

Formulation and in vitro evaluation of curcumin-lactoferrin conjugated nanostructures for cancerous cells.

Curcumin, a natural polyphenol, exhibits anti-oxidant, anti-inflammatory, anti-neoplastic and chemopreventive properties. In fact, targeting of this natural anticancer agent has received a great deal of attention during the recent years. In this study, we proposed that curcumin conjugation with lactoferrin molecules may lead to a potential drug delivery system targeted toward cancerous cells through both active and passive targeting. In this regard, curcumin conjugated lactoferrin was developed via a carbodiimide-based coupling reaction and the resulting conjugates were appraised for their molecular properties as a potential targeted drug delivery system. The mean diameter of the designed nanostructure was about 165 ± 26 nm with a PDI of 0.308 ± 0.045. The conjugated nanostructures showed a considerably improved cytotoxicity on HCT116 cells as illustrated by MTT assay along with a higher level of cellular uptake. Cellular uptake and targeting capability of conjugated samples were further investigated by confocal microscopy and the conjugated curcumin nanostructures showed an enhanced efficacy compared to curcumin. Furthermore, flow cytometry analysis proved that early apoptosis occurred in HCT116 cell line, after 24 h incubation with conjugated curcumin.

Intranasal delivery of α-asarone to the brain with lactoferrin-modified mPEG-PLA nanoparticles prepared by premix membrane emulsification.

Alpha-asarone is a bioactive component of Acorus tatarincuii Schott with low bioavailability, which is often used for treatments of various brain diseases in clinical setting. This study was to formulate biodegradable methoxy polyethylene glycol-polylactic acid (mPEG-PLA) nanoparticles (NPs) surface-modified by lactoferrin (Lf), for delivering α-asarone into the brain following intranasal administration. Alpha-asarone NPs were prepared by premix membrane emulsification. The relative parameters were optimized by a Box-Behnken experimental design. The particle size, zeta potential, and dispersibility index of NPs and Lf-NPs were characterized. Their ex vivo permeation, pharmacokinetics, distribution in the brain and other tissue, brain targeting, and toxicity were investigated. Following intranasal administration, Lf-NPs had a better permeability and no significant poor bioavailability compared to NPs; the area under curve from 0 to 12 h of α-asarone in Lf-NPs of the olfactory bulb, hippocampus, olfactory bundles, and thalamus were 2.14-, 4.17-, 3.62-, and 1.96-fold of those in NP group, respectively. Lactoferrin could enhance the efficacy of brain targeting with NPs and reduce its liver accumulation. Toxicity of NPs on nasal mucosal cilia and epithelial cells was also decreased by Lf. To summarize, these results demonstrate that Lf-NPs of α-asarone have potential as a carrier for nose-to-brain delivery of α-asarone for brain diseases.

Overcoming blood brain barrier with a dual purpose Temozolomide loaded Lactoferrin nanoparticles for combating glioma (SERP-17-12433).

Targeted delivery of drugs to the brain is challenging due to the restricted permeability across the blood brain barrier (BBB). Gliomas are devastating cancers and their positive treatment outcome using Temozolomide (TMZ) is limited due to its short plasma half-life, systemic toxicity and limited access through the blood-brain barrier (BBB). Nanoparticles made of Lactoferrin (Lf) protein, have been shown to enhance the pharmacological properties of drugs. Here, we report the specific ability of Lf nanoparticles to cross BBB and target over-expressed Lf receptors on glioma for enhanced TMZ delivery. TMZ-loaded Lf nanoparticles (TMZ-LfNPs) were prepared by our previously reported sol-oil method. While the Lf protein in the NP matrix aids in transcytosis across the BBB and preferential tumor cell uptake, the pH responsiveness leads to TMZ release exclusively in the tumor microenvironment. Delivery through LfNPs results in an enhanced and sustained intracellular concentration of TMZ in GL261 cells in vitro along with improving its in vivo pharmacokinetics and brain accumulation. TMZ-LfNPs treatment results in a significant reduction of tumor volume, higher tumor cell apoptosis and improved median survival in glioma bearing mice. These results demonstrate that LfNPs present an efficient TMZ delivery platform for an effective treatment of gliomas.

Salivary lactoferrin is transferred into the brain via the sublingual route.

Lactoferrin (LF) is produced by exocrine glands including salivary gland, and has various functions including infection defense. However, the transfer of LF from peripheral organs into the brain remains unclear. To clarify the kinetics of salivary LF (sLF), we investigated the consequences of sialoadenectomy and bovine LF (bLF) sublingual administration in rats. The salivary glands were removed from male Wistar rats, and we measured rat LF levels in the blood and brain at 1 week post-surgery. We also examined the transfer of LF into the organs of the rats after sublingual administration of bLF. Rat LF levels in the blood and brain were significantly reduced by sialoadenectomy. Sublingual bLF administration significantly increased bLF levels in the brain, which then decreased over time. These results indicate that LF is transferred from the sublingual mucosa to the brain, in which favorable effects of sLF on brain will be expected via the sublingual mucosa.

Formulation for Oral Delivery of Lactoferrin Based on Bovine Serum Albumin and Tannic Acid Multilayer Microcapsules.

Lactoferrin (Lf) has considerable potential as a functional ingredient in food, cosmetic and pharmaceutical applications. However, the bioavailability of Lf is limited as it is susceptible to digestive enzymes in gastrointestinal tract. The shells comprising alternate layers of bovine serum albumin (BSA) and tannic acid (TA) were tested as Lf encapsulation system for oral administration. Lf absorption by freshly prepared porous 3 µm CaCO3 particles followed by Layer-by-Layer assembly of the BSA-TA shells and dissolution of the CaCO3 cores was suggested as the most efficient and harmless Lf loading method. The microcapsules showed high stability in gastric conditions and effectively protected encapsulated proteins from digestion. Protective efficiency was found to be 76 ± 6% and 85 ± 2%, for (BSA-TA)4 and (BSA-TA)8 shells, respectively. The transit of Lf along the gastrointestinal tract (GIT) of mice was followed in vivo and ex vivo using NIR luminescence. We have demonstrated that microcapsules released Lf in small intestine allowing 6.5 times higher concentration than in control group dosed with the same amount of free Lf. Significant amounts of Lf released from microcapsules were then absorbed into bloodstream and accumulated in liver. Suggested encapsulation system has a great potential for functional foods providing lactoferrin.

Iron bioavailability from supplemented formula milk: effect of lactoferrin addition.

PURPOSE: In this work, the absorption and/or bioavailability of iron from two chemical species, 57Fe-Lf (apo-lactoferrin) complex and 57FeSO4 at low and high dose, and in Lf excess were investigated in lactating wistar rats. METHODS: The methodology used is based on the use of stable isotopes in combination with the approach "isotope pattern deconvolution" and ICP-MS for detection. This approach provides quantitative information about exogenous (57Fe) and endogenous iron (natFe) distribution in fluids and tissues in the iron-supplemented rat groups. RESULTS: The observed results with supplemented rats were compared with those found in rats receiving maternal feeding. Interestingly, differences were found between groups in iron for transport and storage compartments, but not in the functional one, depending upon the dose of iron administered and the chemical species. CONCLUSION: Considering the results obtained, supplementation with iron salts in excess of Lf appears to be the best way of iron supplementation of formula milk.