Nanotechnology-augmented sonodynamic therapy and associated immune-mediated effects for the treatment of pancreatic ductal adenocarcinoma

PURPOSE: Sonodynamic therapy (SDT) is emerging as a cancer treatment alternative with significant advantages over conventional therapies, including its minimally invasive and site-specific nature, its radical antitumour efficacy with minimal side effects, and its capacity to raise an antitumour immune response. The study explores the efficacy of SDT in combination with nanotechnology against pancreatic ductal adenocarcinoma. METHODS: A nanoparticulate formulation (HPNP) based on a cathepsin B-degradable glutamate-tyrosine co-polymer that carries hematoporphyrin was used in this study for the SDT-based treatment of PDAC. Cathepsin B levels in BxPC-3 and PANC-1 cells were correlated to cellular uptake of HPNP. The HPNP efficiency to induce a sonodynamic effect at varying ultrasound parameters, and at different oxygenation and pH conditions, was investigated. The biodistribution, tumour accumulation profile, and antitumour efficacy of HPNP in SDT were examined in immunocompetent mice carrying bilateral ectopic murine pancreatic tumours. The immune response profile of excised tumour tissues was also examined. RESULTS: The HPNP formulation significantly improved cellular uptake of hematoporphyrin for both BxPC-3 and PANC-1 cells, while increase of cellular uptake was positively correlated in PANC-1 cells. There was a clear SDT-induced cytotoxicity at the ultrasound conditions tested, and the treatment impaired the capacity of both BxPC-3 and PANC-1 cells to form colonies. The overall acoustic energy and pulse length, rather than the power density, were key in eliciting the effects observed in vitro. The SDT treatment in combination with HPNP resulted in 21% and 27% reduction of the target and off-target tumour volumes, respectively, within 24 h. A single SDT treatment elicited an antitumour effect that was characterized by an SDT-induced decrease in immunosuppressive T cell phenotypes. CONCLUSION: SDT has significant potential to serve as a monotherapy or adjunctive treatment for inoperable or borderline resectable PDAC

The role of retinoids and related type II nuclear receptors in the regulation of inflammatory responses and immune tolerance : relevance to multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS), culminating in neurodegenerative disability. The combination of T-cell mediated autoimmune background and defects in immune regulation emerges as a hallmark feature of MS pathogenesis. This paradigm has opened a new avenue for exploitation of immunomodutatory agents in the MS therapy. Retinoids, the compounds related to the vitamin A, may have the potential to control cellular immune responses. They activate a group of endogenous ligand-inducible Type II Nuclear Receptors (NRs), which can act as a molecular switch at the cell transcription level. This study aimed to examine the role of endogenous retinoid system (ERS) in human immune regulation and address its relevance for modulating the immunopathogenic factors and restoring the immune balance in MS. Protein and transcript profiling along with in vitro studies of T cell dynamics in peripheral blood have revealed signature features of MS from the immunological perspective. A compelling body of evidence in this study points to the bias towards proinflammatory Th17 and Th1 cell responses at the expense of anti-inflammatory Tregs in periphera l blood as the mediators of MS immunopathogenesis. AtRA administration in vitro selectively altered the dysregulated immune dynamics: antagonised the pathogenic T cell subsets and promoted Tregs, modulating the cell ratio, effector phenotypes and functions. AtRA efficacy in the restoration of T cell homeostasis in vitro has been replicated in MS, proving responsiveness to the retinoid treatment in majority of MS patients. The study offers a better understanding of molecular mechanisms underlying the retinoid-mediated T cell immunomodulation. NR signalling has been explored in functional assays in vitro and revealed preferential anti-inflammatory polarisation of T cell response. The effector components of ERS - NRs transducing retinoid signals and t heir ligands - were monitored in vivo in peripheral blood cells in health and MS. This work has provided insights into previously unexplored interplay between the endogenous retinoid system and immune profile in the periphery and its translation into neurological pathology in MS. Altogether, the study concludes that retinoid signalling appears to be a significant player in molecular control of inflammation, governing the fate of its key T cell mediators. The accumulated findings suggest that retinoid-based strategies may offer a promising alternative for current approaches to MS treatment.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The role of retinoids and related type II nuclear receptors in the regulation of inflammatory responses and immune tolerance : relevance to multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS), culminating in neurodegenerative disability. The combination of T-cell mediated autoimmune background and defects in immune regulation emerges as a hallmark feature of MS pathogenesis. This paradigm has opened a new avenue for exploitation of immunomodutatory agents in the MS therapy. Retinoids, the compounds related to the vitamin A, may have the potential to control cellular immune responses. They activate a group of endogenous ligand-inducible Type II Nuclear Receptors (NRs), which can act as a molecular switch at the cell transcription level. This study aimed to examine the role of endogenous retinoid system (ERS) in human immune regulation and address its relevance for modulating the immunopathogenic factors and restoring the immune balance in MS. Protein and transcript profiling along with in vitro studies of T cell dynamics in peripheral blood have revealed signature features of MS from the immunological perspective. A compelling body of evidence in this study points to the bias towards proinflammatory Th17 and Th1 cell responses at the expense of anti-inflammatory Tregs in periphera l blood as the mediators of MS immunopathogenesis. AtRA administration in vitro selectively altered the dysregulated immune dynamics: antagonised the pathogenic T cell subsets and promoted Tregs, modulating the cell ratio, effector phenotypes and functions. AtRA efficacy in the restoration of T cell homeostasis in vitro has been replicated in MS, proving responsiveness to the retinoid treatment in majority of MS patients. The study offers a better understanding of molecular mechanisms underlying the retinoid-mediated T cell immunomodulation. NR signalling has been explored in functional assays in vitro and revealed preferential anti-inflammatory polarisation of T cell response. The effector components of ERS - NRs transducing retinoid signals and t heir ligands - were monitored in vivo in peripheral blood cells in health and MS. This work has provided insights into previously unexplored interplay between the endogenous retinoid system and immune profile in the periphery and its translation into neurological pathology in MS. Altogether, the study concludes that retinoid signalling appears to be a significant player in molecular control of inflammation, governing the fate of its key T cell mediators. The accumulated findings suggest that retinoid-based strategies may offer a promising alternative for current approaches to MS treatment.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The potential for a protective vaccine for rhinovirus infections

Rhinovirus (RV) infections impose a major disease burden as they cause around three out of four common colds and are responsible for the majority of acute exacerbations of chronic obstructive pulmonary disease (COPD) and asthma. RVs therefore are associated with an enormous economic cost in missed work or school and medical attention. Prophylactic vaccination against infection is arguably the most effective medical intervention ever developed, and has proven enormously effective in protecting against a large number of diseases. However, at the present time no effective vaccine exists for RVs. This is largely due to the existence of 100 serotyped antigenically distinct RV strains - such variability means that a vaccine designed to elicit immune responses against a particular RV is unlikely to be able to provide protection against the full range of virus subtypes successfully. In fact, this phenomenon was observed as early as 1965 when immunising with formalin inactivated whole RV and is confirmed by the knowledge that the immunity induced following RV infection does not significantly protect from future infection by different RV serotypes. More sophisticated attempts at immunisation with multiple inactivated RV serotypes also failed to induce significant cross-serotype protection. Thus, an effective cross-serotype responsive RV vaccine has remained elusive. The relatively recent description of a new clade of RV types (RV-C) has increased the number of identified strains/serotypes to ~160. Perhaps the quest for a RV vaccine has been dismissed as too difficult or even impossible, but new developments suggest that it may be feasible to generate a significant breadth of immune protection

Gene Targeting to the Cerebral Cortex Following Intranasal Administration of Polyplexes

Gene delivery to the cerebral cortex is challenging due to the blood brain barrier and the labile and macromolecular nature of DNA. Here we report gene delivery to the cortex using a glycol chitosan—DNA polyplex (GCP). In vitro, GCPs carrying a reporter plasmid DNA showed approximately 60% of the transfection efficiency shown by Lipofectamine lipoplexes (LX) in the U87 glioma cell line. Aiming to maximise penetration through the brain extracellular space, GCPs were coated with hyaluronidase (HYD) to form hyaluronidase-coated polyplexes (GCPH). The GCPH formulation retained approximately 50% of the in vitro hyaluronic acid (HA) digestion potential but lost its transfection potential in two-dimensional U87 cell lines. However, intranasally administered GCPH (0.067 mg kg−1 DNA) showed high levels of gene expression (IVIS imaging of protein expression) in the brain regions. In a separate experiment, involving GCP, LX and naked DNA, the intranasal administration of the GCP formulation (0.2 mg kg−1 DNA) resulted in protein expression predominantly in the cerebral cortex, while a similar dose of intranasal naked DNA led to protein expression in the cerebellum. Intranasal LX formulations did not show any evidence of protein expression. GCPs may provide a means to target protein expression to the cerebral cortex via the intranasal route

Incorporation of cisplatin into the metal-organic frameworks UiO66-NH2 and UiO66 – encapsulation vs. conjugation.

The authors wish to thank the EPSRC (EP/K005499/1 and EP/K025112/1) and the British Heart Foundation (NH/11/8/29253) for funding.This work demonstrates synthetic strategies for the incorporation of an anticancer drug, cisplatin, and a Pt(IV) cisplatin prodrug into two zirconium-based metal-organic-frameworks (MOFs): UiO66 and UiO66-NH2. Cisplatin was chosen due to its reported high potency in killing ca. 95% of different cancers. Two approaches for its incorporation were investigated: conjugation and encapsulation. In the conjugation route, a Pt(IV) cisplatin prodrug was incorporated into UiO66-NH2 utilising its amine group in an amide-coupling reaction. In the second case, cisplatin was encapsulated into the large cavities of both MOFs. The presence of platinum was confirmed by energy-dispersive X-ray spectroscopy and microwave plasma-atomic emission spectroscopy. The cytotoxicity of the formulations was assessed on the A549 lung cancer cell line. The results show that the system in which cisplatin is conjugated to UiO66-NH2 is more efficient in inducing cell death than the materials where cisplatin is encapsulated into the pores of the MOFs. This is consistent with the higher drug loading achieved with the conjugation technique. One disadvantage of cisplatin therapy is that it may lead to thrombosis and, as a consequence, to heart attack and cardiac arrest. To ameliorate this potential side effect, we investigated the incorporation of NO (which has been widely researched for its antithrombotic properties) into the drug-loaded MOFs. All the cisplatin or pro-drug loaded MOFs are able to entrap and then release NO. Furthermore, the amount of NO released from these formulations is much greater than from the pure MOFs. As a result, the drug delivery systems developed in this work have potentially potent double functionality.Publisher PDFPeer reviewe

Particulate levodopa nose-to-brain delivery targets dopamine to the brain with no plasma exposure

Levodopa (L-DOPA) is an oral Parkinson's Disease drug that generates the active metabolite - dopamine (DA) in vivo. However, oral L-DOPA exhibits low oral bioavailability, limited brain uptake, peripheral DA-mediated side effects and its poor brain bioavailability can lead to long-term complications. Here we show that L-DOPA forms stable (for at least 5 months) 300 nm nanoparticles when encapsulated within N-palmitoyl-N-monomethyl-N,N-dimethyl-N,N,N-trimethyl-6-O-glycolchitosan (GCPQ). A nano-in-microparticle GCPQ-L-DOPA formulation (D50 = 7.2 µm), prepared by spray-drying, was stable for one month when stored at room and refrigeration temperatures and was capable of producing the original GCPQ-L-DOPA nanoparticles upon aqueous reconstitution. Nasal administration of reconstituted GCPQ-L-DOPA nanoparticles to rats resulted in significantly higher DA levels in the brain (Cmax of 94 ng g-1 above baseline levels 2 h post-dosing) when compared to nasal administration of L-DOPA alone, with DA being undetectable in the brain with the latter. Furthermore, nasal GCPQ-L-DOPA resulted in higher levels of L-DOPA in the plasma (a 17-fold increase in the Cmax, when compared to L-DOPA alone) with DA undetectable in the plasma from both formulations. These data provide evidence of effective delivery of DA to the brain with the GCPQ-L-DOPA formulation