Challenges in Translating from Bench to Bed-Side: Pro-Angiogenic Peptides for Ischemia Treatment.

We describe progress and obstacles in the development of novel peptide-hydrogel therapeutics for unmet medical needs in ischemia treatment, focusing on the development and translation of therapies specifically in peripheral artery disease (PAD). Ischemia is a potentially life-threatening complication in PAD, which affects a significant percentage of the elderly population. While studies on inducing angiogenesis to treat PAD were started two decades ago, early results from animal models as well as clinical trials have not yet been translated into clinical practice. We examine some of the challenges encountered during such translation. We further note the need for sustained angiogenic effect involving whole growth factor, gene therapy and synthetic growth factor strategies. Finally, we discuss the need for tissue depots for de novo formation of microvasculature. These scaffolds can act as templates for neovasculature development to improve circulation and healing at the preferred anatomical location.

Randomized Controlled Trial of Talactoferrin Oral Solution in Preterm Infants.

OBJECTIVE: To evaluate the safety and explore the efficacy of recombinant human lactoferrin (talactoferrin [TLf]) to reduce infection. STUDY DESIGN: We conducted a randomized, double blind, placebo-controlled trial in infants with birth weight of 750-1500 g. Infants received enteral TLf (n = 60) or placebo (n = 60) on days 1 through 28 of life; the TLf dose was 150 mg/kg every 12 hours. Primary outcomes were bacteremia, pneumonia, urinary tract infection, meningitis, and necrotizing enterocolitis (NEC). Secondary outcomes were sepsis syndrome and suspected NEC. We recorded clinical, laboratory, and radiologic findings, along with diseases and adverse events, in a database used for statistical analyses. RESULTS: Demographic data were similar in the 2 groups of infants. We attributed no enteral or organ-specific adverse events to TLf. There were 2 deaths in the TLf group (1 each due to posterior fossa hemorrhage and postdischarge sudden infant death), and 1 death in the placebo group, due to NEC. The rate of hospital-acquired infections was 50% lower in the TLf group compared with the placebo group (P < .04), including fewer blood or line infections, urinary tract infections, and pneumonia. Fourteen infants in the TLf group weighing <1 kg at birth had no gram-negative infections, compared with only 3 of 14 such infants in the placebo group. Noninfectious outcomes were not statistically significantly different between the 2 groups, and there were no between-group differences in growth or neurodevelopment over a 1-year posthospitalization period. CONCLUSION: We found no clinical or laboratory toxicity and a trend toward less infectious morbidity in the infants treated with TLf. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00854633.

Oral lactoferrin results in T cell-dependent tumor inhibition of head and neck squamous cell carcinoma in vivo.

PURPOSE: Human lactoferrin is a naturally occurring glycoprotein that inhibits cancer growth. Our purpose was to evaluate recombinant human lactoferrin as a chemotherapeutic agent against head and neck squamous cell carcinoma. EXPERIMENTAL DESIGN: Controlled experiments both in vitro and in the murine model evaluating both the effect and mechanism of lactoferrin on cancer growth. RESULTS: In both human and murine cell lines, lactoferrin induced dose-dependent growth inhibition. Using flow cytometric analysis, lactoferrin was shown to induce G(1)-G(0) growth arrest. This arrest seemed to be modulated by down-regulation of cyclin D1. In the in vitro model, luminex data revealed that lactoferrin inhibited cellular release of proinflammatory and prometastatic cytokines, including interleukin-8, interleukin-6, granulocyte macrophage colony-stimulating factor, and tumor necrosis factor-alpha. Lactoferrin up-regulated the cellular activation of nuclear factor-kappaB within 4 h of cellular exposure. In C3h/HeJ mice implanted with SCCVII tumors, orally delivered lactoferrin inhibited tumor growth by 75% compared with control mice. Immunohistochemical analysis of harvested tumors revealed up to 20-fold increases of lymphocytes within treated animals. When mice were depleted of CD3(+) cells, all lactoferrin-induced tumor inhibition was abrogated. CONCLUSION: We conclude that human recombinant lactoferrin can inhibit the growth of head and neck squamous cell carcinoma via direct cellular inhibition as well as systemically via immunomodulation. Our data support the study of human lactoferrin as an immunomodulatory compound with therapeutic potential.

Essential properties of drug-targeting delivery systems.

How, if at all, can drug delivery help to create ideal drugs? After four decades of trying, an effective site-specific drug-delivery system has not yet been developed. This review draws attention to the pharmacokinetic conditions that must be met to achieve a successful performance by site-selective drug-carrier delivery systems. In a drug-carrier approach, a drug is attached to a macromolecular carrier via a chemically labile linker. The carrier transports the drug to its site of action and releases it at the target site. For this simple approach to work, several fundamental conditions (nonspecific interactions, target site access, drug release and drug suitability) must be satisfied. The importance of these essential requirements, not always recognized in the development of drug-delivery systems, is discussed and illustrated by recent examples selected from the literature.

Lactoferrin-enhanced anoikis: a defense against neonatal necrotizing enterocolitis.

Enteral nutrition with human milk lowers the incidence of necrotizing enterocolitis in preterm human infants. Lactoferrin, the major whey protein in human milk, has many functions related to host defense against bacterial infection. Here, we hypothesize that lactoferrin also helps terminate bacterial invasion of enterocytes via a detachment-induced apoptosis called anoikis. Death of infected epithelia by anoikis prevents local spread of bacterial pathogens because the bacteria are trapped within the cell. Such infected, apoptotic and sloughed epithelia also cannot infect the lower gastrointestinal tract, and the epithelia exit the body in the stool. Currently, anoikis is a phenomenon related to the renewal of enterocytes, and it is not recognized as an anti-bacterial host defense. We suggest that anoikis of infected enterocytes is a process in which lactoferrin plays an important role. In a pilot study in which neonatal rats were pre-treated with intra-gastric recombinant human lactoferrin, we found evidence of epithelia with anoikis in ileal fluid after enteric infection. This finding was rarely seen in infected neonatal rats without pre-treatment with lactoferrin. Quantitative analysis of intestinal lavage specimens and quantitative stereology of apoptotic epithelia in this model will be required to verify the theory. We propose that oral use of recombinant human lactoferrin might have these hypothesized and other anti-bacterial effects in preterm infants, and hence, this protein might prevent necrotizing enterocolitis in preterm infants who cannot take human milk.

Nanotechnology and site-targeted drug delivery.

Nanotechnology, building on its ability to control or manipulate structures at the atomic level, promises to develop effective drug-delivery systems. This is to be achieved through creating structures that have novel properties because of their small size. This is not an entirely new concept in site-targeted drug delivery, and this critical review examines recent contributions made by 'nanotechnology' to solve critical issues concerning the development of therapeutically effective and acceptable site-targeted drug delivery systems. It is shown that very little progress has been made. For nanotechnology rationally to generate materials useful in human therapy it will need to progress in full recognition of all the requirements biology places on the acceptability of exogenous materials.

Oral lactoferrin inhibits growth of established tumors and potentiates conventional chemotherapy.

In this work, we investigated the anticancer activity of orally administered recombinant human lactoferrin (rhLF) alone and in combination with chemotherapy in tumor-bearing mice. rhLF inhibited the growth of squamous cell carcinoma (O12) tumors in T cell-immunocompromised nu/nu mice by 80% when administered at 1,000 mg/kg (2.9 g/m2) by oral gavage twice daily for 8 days (p < 0.001). Similar activity was observed in syngeneic, immunocompetent BALB/c mice, where orally administered rhLF (1,000 mg/kg, 2.9 g/m2 once daily) halted the growth of mammary adenocarcinoma TUBO. Oral rhLF (200 mg/kg, 0.57 g/m2) was also used alone and in combination with cis-platinum (5 mg/kg) to treat head-and-neck squamous cell carcinoma in a syngeneic murine model. Monotherapy with oral rhLF or cis-platinum caused 61% or 66% tumor growth inhibition over placebo, respectively. Mice receiving both therapies showed 79% growth inhibition, a statistically significant improvement over each drug alone. We then demonstrated that administration of oral rhLF (300 mg/kg, 0.86 g/m2) to tumor-bearing or naive mice resulted in (i) significantly increased production of IL-18 in the intestinal tract, (ii) systemic NK cell activation and (iii) circulating CD8+ T-cell expansion. These data suggest that oral rhLF is an immunomodulatory agent active against cancer as a single agent and in combination chemotherapy, exerting its systemic effect through stimulation of IL-18 and other cytokines in the gut enterocytes. rhLF has been administered orally to 211 people without a single serious drug-related adverse event. Thus, rhLF shows promise as a safe and well-tolerated novel immunomodulatory anticancer agent.