Aerosol therapy for malignancy involving the lungs

Smart Sensors and Microtechnologies in the Precision Medicine Approach against Lung Cancer

BACKGROUND AND RATIONALE

The therapeutic interventions against lung cancer are currently based on a fully personalized approach to the disease with considerable improvement of patients' outcome. Alongside continuous scientific progresses and research investments, massive technologic efforts, innovative challenges, and consolidated achievements together with research investments are at the bases of the engineering and manufacturing revolution that allows a significant gain in clinical setting.

AIM AND METHODS

The scope of this review is thus to focus, rather than on the biologic traits, on the analysis of the precision sensors and novel generation materials, as semiconductors, which are below the clinical development of personalized diagnosis and treatment. In this perspective, a careful revision and analysis of the state of the art of the literature and experimental knowledge is presented.

RESULTS

Novel materials are being used in the development of personalized diagnosis and treatment for lung cancer. Among them, semiconductors are used to analyze volatile cancer compounds and allow early disease diagnosis. Moreover, they can be used to generate MEMS which have found an application in advanced imaging techniques as well as in drug delivery devices.

CONCLUSIONS

Overall, these issues represent critical issues only partially known and generally underestimated by the clinical community. These novel micro-technology-based biosensing devices, based on the use of molecules at atomic concentrations, are crucial for clinical innovation since they have allowed the recent significant advances in cancer biology deciphering as well as in disease detection and therapy. There is an urgent need to create a stronger dialogue between technologists, basic researchers, and clinicians to address all scientific and manufacturing efforts towards a real improvement in patients' outcome. Here, great attention is focused on their application against lung cancer, from their exploitations in translational research to their application in diagnosis and treatment development, to ensure early diagnosis and better clinical outcomes.

Neurokinin 1 and 2 Receptors Are Involved in PEG2- and Citric Acid-Induced Cough and Ventilatory Responses

Exposure to aerosolized citric acid (CA, 150mM) and prostaglandin E₂ (PGE₂, 0.43mM) for 10min in guinea pigs reportedly produces the distinct cough patterns (Type I vs. II) and ventilatory responses (long-lasting hyperventilation vs. brief tachypnea) even though triggering the same cough numbers. Type I and II coughs are primarily mediated by activation of TRPV1 and EP3 receptors (a PGE₂ receptor) of vagal C-fibers respectively. Substance P (SP) and neurokinin A (NKA) released by vagal pulmonary sensory fibers peripherally are capable of affecting CA-induced cough and ventilation via preferentially activating neurokinin 1 and 2 receptors (NK₁R and NK₂R) respectively. This study aimed to define the impacts of CA- and PGE₂-exposure on pulmonary SP and NKA levels and the roles of NK₁R and NK₂R in modulating CA- and PGE₂-evoked cough and ventilatory responses. In unanesthetized guinea pigs, we determined: 1) pulmonary SP and NKA contents induced by the CA- or PGE₂-exposure; 2) effects of CP-99994 and SR-48968 (a NK₁R and a NK₂R antagonist respectively) given by intraperitoneal injection (IP) or aerosol inhalation (IH) on the CA- and PGE₂-evoked cough and ventilatory responses; and 3) immunocytochemical expressions of NK₁R/NK₂R in vagal C-neurons labeled by TRPV1 or EP3 receptors. We found that CA- and PGE₂-exposure evoked Type I and II cough respectively associated with different degrees of increases in pulmonary SP and NKA. Applications of CP-99994 and SR-48968 via IP and IH efficiently suppressed the cough responses to CA with less impact on the cough response to PGE₂. These antagonists inhibited or blocked the ventilatory response to CA and caused hypoventilation in response to PGE₂. Moreover, NK₁R and NK₂R were always co-expressed in vagal C-neurons labeled by TRPV1 or EP3 receptors. These results suggest that SP and NKA endogenously released by CA- and PGE₂-exposure play important roles in generating the cough and ventilatory responses to CA and PGE₂, at least in part, via activation of NK₁R and NK₂R expressed in vagal C-neurons (pulmonary C-neurons).

Back to the Future: Rethinking the Great Potential of lncRNAS for Optimizing Chemotherapeutic Response in Ovarian Cancer

Ovarian cancer (OC) is one of the most fatal cancers in women worldwide. Currently, platinum- and taxane-based chemotherapy is the mainstay for the treatment of OC. Yet, the emergence of chemoresistance results in therapeutic failure and significant relapse despite a consistent rate of primary response. Emerging evidence substantiates the potential role of lncRNAs in determining the response to standard chemotherapy in OC. The objective of this narrative review is to provide an integrated, synthesized overview of the current state of knowledge regarding the role of lncRNAs in the emergence of resistance to platinum- and taxane-based chemotherapy in OC. In addition, we sought to develop conceptual frameworks for harnessing the therapeutic potential of lncRNAs in strategies aimed at enhancing the chemotherapy response of OC. Furthermore, we offered significant new perspectives and insights on the interplay between lncRNAs and the molecular circuitries implicated in chemoresistance to determine their impacts on therapeutic response. Although this review summarizes robust data concerning the involvement of lncRNAs in the emergence of acquired resistance to platinum- and taxane-based chemotherapy in OC, effective approaches for translating these lncRNAs into clinical practice warrant further investigation.

Molecular insights and novel approaches for targeting tumor metastasis

In recent years, due to the effective drug delivery and preciseness of tumor sites or microenvironment, the targeted drug delivery approaches have gained ample attention for tumor metastasis therapy. The conventional treatment approaches for metastasis therapy have reported with immense adverse effects because they exhibited maximum probability of killing the carcinogenic cells along with healthy cells. The tumor vasculature, comprising of vasculogenic impressions and angiogenesis, greatly depends upon the growth and metastasis in the tumors. Therefore, various nanocarriers-based delivery approaches for targeting to tumor vasculature have been attempted as efficient and potential approaches for the treatment of tumor metastasis and the associated lesions. Furthermore, the targeted drug delivery approaches have found to be most apt way to overcome from all the limitations and adverse effects associated with the conventional therapies. In this review, various approaches for efficient targeting of pharmacologically active chemotherapeutics against tumor metastasis with the cohesive objectives of prognosis, tracking and therapy are summarized.

A perspective on magnetic core-shell carriers for responsive and targeted drug delivery systems

Magnetic core-shell nanocarriers have been attracting growing interest owing to their physicochemical and structural properties. The main principles of magnetic nanoparticles (MNPs) are localized treatment and stability under the effect of external magnetic fields. Furthermore, these MNPs can be coated or functionalized to gain a responsive property to a specific trigger, such as pH, heat, or even enzymes. Current investigations have been focused on the employment of this concept in cancer therapies. The evaluation of magnetic core-shell materials includes their magnetization properties, toxicity, and efficacy in drug uptake and release. This review discusses some categories of magnetic core-shell drug carriers based on Fe2O3 and Fe3O4 as the core, and different shells such as poly(lactic-co-glycolic acid), poly(vinylpyrrolidone), chitosan, silica, calcium silicate, metal, and lipids. In addition, the review addresses their recent potential applications for cancer treatment.

Matrix metalloproteinase 2/9-triggered-release micelles for inhaled drug delivery to treat lung cancer: preparation and in vitro/in vivo studies

Background

Improvement in drug accumulation in the lungs through inhalation administration and high expression of MMP2 and MMP9 in lung tumors have both been widely reported.

Methods

MMP2/9-triggered-release micelles were constructed and in vitro and in vivo studies of inhalation administration against lung tumor carried out. Pluronic P123 (P123) was modified with GPLGIAGQ-NH2 (GQ8) peptide to obtain P123-GQ8 (PG). MMP2/9-triggered-release micelles were constructed using PG and succinylated gelatin (SG) and loading paclitaxel (Ptx). To study biodistribution of micelles, DiR encapsulated in micelles was dosed to rats via intravenous injection or inhalation before ex vivo imaging for detecting DiR quantity in lungs. And B16F10 lung cancer-bearing nude mice were chosen as animal models to evaluate in vivo efficacy of MMP2/9-triggered-release micelles.

Results

Ptx-release efficiency from PG-SG-Ptx micelles was MMP2/9-concentration-dependent. For A549 cells, PG-SG-Ptx cytotoxicity was significantly greater (P<0.001) compared to P123-Ptx. Aerosol inhalation was chosen as the method of administration. In biodistribution experiment, DiR quantity in lungs was 5.8%±0.4% of that in major organs, while the ratio was 38.8%±0.5% for inhalation. For B16F10 lung cancer-bearing nude mice, the efficacy of inhalation of PG-SG-Ptx was significantly higher (P<0.001) than Taxol inhalation and injected PG-SG-Ptx. Inhaled PG-SG-Ptx also significantly inhibited the expression of Pgp in lung cancer.

Conclusion

Inhalation of MMP2/9-triggered-release micelles increased tumor sensitivity to chemotherapeutics and reduced the toxicity of chemotherapy to healthy lung cells, which has great potential in lung cancer therapy.

Calcium Phosphate Particles as Pulmonary Delivery System for Interferon-α in Mice

Systemically administered interferons are rapidly cleared from the circulation thus requiring frequent dosing to maintain the therapeutic levels of circulating interferon. This is particularly problematic for their use in the treatment of chronic diseases. The purpose of this study was to evaluate the potential of proprietary calcium phosphate (CaP) particles to deliver biologically active interferon alpha (IFNα) via the lungs into systemic circulation. Recombinant human IFNα-2a was formulated with proprietary CaP particles. In vitro biological activity of IFNα was assessed for its potential to activate IFN-induced cellular pathways in HEK-Blu-IFN α/β cell cultures. Antiviral activity was evaluated against vesicular stomatitis virus (VSV) infection of HeLa cells. Male BALB/c mice were used to evaluate the absorption of IFNα from CaP-IFNα across the lungs following intratracheal (IT) instillation. Serum IFNα concentrations up to 9 h post-treatment were determined. Data were analyzed to obtain pharmacokinetic (PK) parameters. Data from these studies indicated that IFNα formulated with CaP retains its biological activity, and it is transported into circulation in a dose-dependent manner. PK analysis showed larger than two-fold area under the serum concentration-time curve (AUC) for CaP-IFNα compared to non-formulated IFNα administered IT. The IFNα formulated with CaP had two-fold longer half-life (t1/2) and mean residence time (MRT) relative to IFNα alone administered by injection. Clearance of CaP-IFNα was slower than IFNα administered IM or IT. Relative bioavailability of CaP-IFNα was 1.3-fold of IFNα injection and twofold of IFNα administered IT. Furthermore, inhalation of aerosolized CaP did not indicate any lung toxicity in animals.

Preparation and Characterization of Magnetic Nano-in-Microparticles for Pulmonary Delivery

The purpose of this chapter is to detail the formulation and characterization of a magnetically-targeted drug delivery vehicle, termed nano-in-microparticles (NIMs), for pulmonary drug delivery. Currently, chemotherapeutics and antibiotics are delivered systemically and result in whole body side-effects. NIMs are formulated with superparamagnetic iron oxide nanoparticles, termed SPIONs, making these particles targetable to specific lung regions using a strong external magnet. Additionally, these particles can be formulated to contain any drug or therapeutic agent, such that a therapeutic dose can be delivered to a specific tissue location using the SPIONs-magnet interaction. Finally, these particles are in the appropriate size range for pulmonary delivery, making NIMs therapeutics feasibly inhalable.To generate these particles a solution containing lactose, SPIONs, and a microsphere dye (used as a drug surrogate) is spray-dried using a laboratory-scale spray dryer. The resulting dry powder microparticles (NIMs) can be characterized for their size and morphological properties by various techniques that are presented in this chapter.The utility of NIMs as a magnetic field-dependent targeting delivery platform in an in vivo mouse model has been demonstrated, and a protocol detailing the intratracheal delivery of NIMs dry powder is included as a separate chapter in this book.

Chemotherapy, Irradiation, and Surgery for Function-preserving Curative Therapy of Primary Extremity Soft Tissue Sarcomas: Initial Treatment With I-MAP and Inhalation GM-CSF During Preoperative Irradiation and Postoperatively

PURPOSE

To determine if aerosol granulocyte macrophage-colony-stimulating factor (GM-CSF) decreases the 2-year pulmonary metastasis rate for soft tissue sarcoma.

PATIENTS AND METHODS

Patients with high-grade soft tissue sarcomas were treated with 2 cycles of ifosfamide, mitomycin, doxorubicin, and cisplatin plus GM-CSF subcutaneous followed by 45 Gy irradiation with concurrent 2 cycles of mitomycin, doxorubicin, and cisplatin followed by surgery +/- intraoperative radiation or brachytherapy. Aerosol GM-CSF (250 mcg twice a day) was administered for 1 week every other week 3× during neoadjuvant therapy and beginning 4 weeks postoperatively every other week 5×.

RESULTS

A total of 39 patients were enrolled between November 2001 and April 2006. The median age was 51 years (range, 19 to 65 y). The median lesion size was 9 cm (range, 2.3 to 26.7 cm). Seventy-six percent experienced grade 3-4 hematologic toxicity. Twenty-four of the first 35 evaluable patients (69%; 95% CI, 41%-84%) were free of pulmonary metastasis at 2 years. A total of 82% (95% CI, 70%-95%) of patients were still alive after 3 years, with a median follow-up of 5.5 years (range, 3.4 to 7.6 y). A total of 58% (95% CI, 44%-76%) of patients remained progression free after 3 years.

CONCLUSIONS

The addition of aerosol GM-CSF to combined chemotherapy, irradiation, and surgery for soft tissue sarcomas did not achieve the study endpoint to decrease the 2-year pulmonary metastasis rate.

Perspective on Nanoparticle Technology for Biomedical Use

This review gives a short overview on the widespread use of nanostructured and nanocomposite materials for disease diagnostics, drug delivery, imaging and biomedical sensing applications. Nanoparticle interaction with a biological matrix/entity is greatly influenced by its morphology, crystal phase, surface chemistry, functionalization, physicochemical and electronic properties of the particle. Various nanoparticle synthesis routes, characterization, and functionalization methodologies to be used for biomedical applications ranging from drug delivery to molecular probing of underlying mechanisms and concepts are described with several examples (150 references).

Targeting tumor metastases: Drug delivery mechanisms and technologies

Primary sites of tumor are the focal triggers of cancers, yet it is the subsequent metastasis events that cause the majority of the morbidity and mortality. Metastatic tumor cells exhibit a phenotype that differs from that of the parent cells, as they represent a resistant, invasive subpopulation of the original tumor, may have acquired additional genetic or epigenetic alterations under exposure to prior chemotherapeutic or radiotherapeutic treatments, and reside in a microenvironment differing from that of its origin. This combination of resistant phenotype and distal location make tracking and treating metastases particularly challenging. In this review, we highlight some of the unique biological traits of metastasis, which in turn, inspire emerging strategies for targeted imaging of metastasized tumors and metastasis-directed delivery of therapeutics.

Loco-regional administration of nanomedicines for the treatment of lung cancer

Lung cancer poses one of the most significant challenges to modern medicine, killing thousands every year. Current therapy involves surgical resection supplemented with chemotherapy and radiotherapy due to high rates of relapse. Shortcomings of currently available chemotherapy protocols include unacceptably high levels of systemic toxicity and low accumulation of drug at the tumor site. Loco-regional delivery of nanocarriers loaded with anticancer agents has the potential to significantly increase efficacy, while minimizing systemic toxicity to anticancer agents. Local drug administration at the tumor site using nanoparticulate drug delivery systems can reduce systemic toxicities observed with intravenously administered anticancer drugs. In addition, this approach presents an opportunity for sustained delivery of anticancer drug over an extended period of time. Herein, the progress in the development of locally administered nanomedicines for the treatment of lung cancer is reviewed. Administration by inhalation, intratumoral injection and means of direct in situ application are discussed, the benefits and drawbacks of each modality are explored.

Inhaled gene therapy in lung cancer: proof-of-concept for nano-oncology and nanobiotechnology in the management of lung cancer

Lung cancer still remains one of the leading causes of death among cancer patients. Although novel targeted therapies have been established in everyday treatment practice, and conventional platinum-based doublets have demonstrated effective results regarding overall and progression-free survival, we have still failed to achieve long-term survival. Therefore, several strategies of applying locoregional therapy are under investigation. Aerosol chemotherapy is already under investigation and, taking this a step further, aerosol gene therapies with multiple delivery systems are being developed. Several efforts have demonstrated its efficiency and effectiveness, but there are still multiple factors that have to be considered and combined to achieve an overall more effective multifunctional treatment. In the current review, we present data regarding aerosol delivery systems, transporters, carriers, vectors, genes, toxicity, efficiency, specificity, lung microenvironment and delivery gene therapy systems. Finally, we present current studies and future perspectives.

Inhaled lipid cisplatin (ILC) in the treatment of patients with relapsed/progressive osteosarcoma metastatic to the lung

BACKGROUND

Osteosarcoma treatment failure is most often from the inability to control metastatic disease in the lungs. Encapsulating cisplatin within lipid complexes and delivering the agent via inhalation targets lung metastases with minimal systemic exposure. An open-label, phase Ib/IIa study was performed to characterize the safety and efficacy of inhaled lipid cisplatin (ILC) in recurrent osteosarcoma patients who only had pulmonary metastases.

PROCEDURE

ILC was administered via nebulizer every 2 weeks (=1 cycle). Response was evaluated radiographically every 2 cycles. Cisplatin levels were measured in patients. When possible, metastasectomy was undertaken in patients after 2 cycles.

RESULTS

Nineteen patients were treated. No patients experienced hematologic toxicity, nephrotoxicity or ototoxicity. Nausea/vomiting (≥grade 3) was attributed to study drug in one patient. Respiratory symptoms were observed in 13/19 patients with only one patient experiencing a ≥grade 3 respiratory symptom (not related to study drug). Systemic cisplatin exposure was minimal. Eleven patients had bulky disease, and all progressed prior to cycle 7. Eight patients had all lesions ≤2 cm. One patient had a sustained partial response. An additional two patients had stable disease after 2 cycles, underwent metastasectomy, and remained free from pulmonary recurrence 1 year after initiation of therapy.

CONCLUSIONS

ILC is well tolerated in heavily treated osteosarcoma patients and did not appear to have the typical toxicities associated with intravenous cisplatin. Three of eight patients with less bulky disease had sustained benefit. Further study of ILC is warranted.

Magnetic core-shell nanoparticles for drug delivery by nebulization

BACKGROUND

Aerosolized therapeutics hold great potential for effective treatment of various diseases including lung cancer. In this context, there is an urgent need to develop novel nanocarriers suitable for drug delivery by nebulization. To address this need, we synthesized and characterized a biocompatible drug delivery vehicle following surface coating of Fe3O4 magnetic nanoparticles (MNPs) with a polymer poly(lactic-co-glycolic acid) (PLGA). The polymeric shell of these engineered nanoparticles was loaded with a potential anti-cancer drug quercetin and their suitability for targeting lung cancer cells via nebulization was evaluated.

RESULTS

Average particle size of the developed MNPs and PLGA-MNPs as measured by electron microscopy was 9.6 and 53.2 nm, whereas their hydrodynamic swelling as determined using dynamic light scattering was 54.3 nm and 293.4 nm respectively. Utilizing a series of standardized biological tests incorporating a cell-based automated image acquisition and analysis procedure in combination with real-time impedance sensing, we confirmed that the developed MNP-based nanocarrier system was biocompatible, as no cytotoxicity was observed when up to 100 μg/ml PLGA-MNP was applied to the cultured human lung epithelial cells. Moreover, the PLGA-MNP preparation was well-tolerated in vivo in mice when applied intranasally as measured by glutathione and IL-6 secretion assays after 1, 4, or 7 days post-treatment. To imitate aerosol formation for drug delivery to the lungs, we applied quercitin loaded PLGA-MNPs to the human lung carcinoma cell line A549 following a single round of nebulization. The drug-loaded PLGA-MNPs significantly reduced the number of viable A549 cells, which was comparable when applied either by nebulization or by direct pipetting.

CONCLUSION

We have developed a magnetic core-shell nanoparticle-based nanocarrier system and evaluated the feasibility of its drug delivery capability via aerosol administration. This study has implications for targeted delivery of therapeutics and poorly soluble medicinal compounds via inhalation route.

Preclinical evaluation of a pulmonary delivered paclitaxel-loaded lipid nanocarrier antitumor effect

Lung cancer remains a leading cause of death due to the low efficacy of chemotherapy, mainly related to the administration route used. Therefore, alternative administration routes are needed. Paclitaxel (PTX) is an insoluble anticancer drug active against solid tumors, such as those found in lung cancer, that has stimulated an intense research effort over recent years. Solid lipid nanoparticles (SLNs) are potential carriers for poorly soluble drugs, being biodegradable systems that served as alternatives to the usual colloidal carriers. That system was used to deliver PTX to the lungs and seem to fulfill the requirements for an optimum particulate carrier. Furthermore, PTX-loaded SLN pulmonary administration provided a target administration, which is expected to avoid high concentration of the drug at nontarget tissues, reducing toxicity, and increasing the drug's therapeutic index. The rationale of this study was to deliver a colloidal system to the lung lymphatics through a pulmonary route for cancer therapy.

FROM THE CLINICAL EDITOR

Paclitaxel-loaded solid lipid nanoparticles were used to target tumors in a murine lung cancer model enabling high PTX concentration in the target with reduced systemic toxicity and increased therapeutic index.

Liposomal formulations of Etoposide and Docetaxel for p53 mediated enhanced cytotoxicity in lung cancer cell lines

The objective of present investigation was to develop and assess comparative enhancement in cytotoxicity of liposomal Etoposide and Docetaxel in non-small cell lung cancer cell lines after pre-treatment and co-administration of p53 tumor suppressor gene and to assess direct lung targeting of optimized formulations by dry powder inhaler technology. Cationic liposomes with and without drug were prepared and allowed to form p53-lipoplex for undertaking cytotoxicity studies in H-1299 (p53 null) and A-549 (p53 wt) cell lines. The optimized lipoplexes showed average size of 200-350 nm, zeta potential of 25-32 mV and sustained drug release up to 16-24 h. The developed liposomes and lipoplexes showed significant intracellular uptake and demonstrated enhanced cytotoxicity of 13-28 % after p53-drug co-administration and 41-63 % after p53 pre-treatment. The p53 mediated enhanced cytotoxicity by increased apoptosis and necrosis was also confirmed using Annexin V - FITC assay. The increased apoptosis suggested restored p53 function and reduced anti-apoptotic drug resistance theirby causing cell sensitization and synergism towards cytotoxicity. The studies conducted above demonstrated significant cell chemo-sensitization after p53 pre-treatment followed by Etoposide/Docetaxel liposomes administration than p53-Etoposide or p53-Docetaxel lipoplex co-administration; more significantly in Docetaxel and in H 1299 cell line. All the formulations when developed as dry powder inhalers showed significant in vitro lung deposition pattern in cascade impactor with fine particle faction of 33-37%. The study opens up a new strategy to treat lung cancer especially in cases of drug resistance. Moreover direct delivery to lung may provide an important role in complete remission of the disease due to target specificity.

Regional Lung Chemotherapy Techniques

Selective delivery of chemotherapy to an affected organ or region of the body promises improved drug efficacy for the targeted area while minimizing the systemic exposure and toxicity. Several intravascular surgical techniques to achieve targeted regional lung chemotherapy have been developed. Investigations have been carried out to determine the feasibility, safety, and efficacy of these techniques in the primary or adjuvant setting with the intent to palliate or cure. This overview describes the history, rationale, technical aspects, and clinical experience of four regional lung chemotherapy techniques delivered by vascular manipulations including bronchial artery infusion, pulmonary artery chemoembolization, isolated lung perfusion, and lung suffusion.

A dose-escalation study of aerosolized sargramostim in the treatment of metastatic melanoma: an NCCTG Study

OBJECTIVES

Early testing of aerosolized sargramostim therapy demonstrated anecdotal clinical responses in patients with metastatic melanoma associated with emergence of systemic antitumor immunity. To improve the clinical and immunologic efficacy of therapy without compromising patient safety, we performed a further dose escalation trial in patients with metastatic melanoma.

METHODS

We conducted a dose-escalation clinical trial of HLA-A2 patients with metastatic melanoma to the lung treated with aerosolized granulocyte macrophage colony stimulating factor (GM-CSF) (500-2000 microg/dose, with increments of 250 microg/dose/cohort) twice/d on days 1 to 7 and 15 to 21 every 28 days until progression or severe toxicity to find a dose where a majority of patients develop antitumor immunity. Five patients were treated per each dose level. Clinical, immune, and safety parameters were examined.

RESULTS

The study accrued 40 patients. Toxicity was acceptable. All doses levels were exhausted without identifying a dose of GM-CSF at which a majority of patients (> or =3 of 5) demonstrated significant up-regulation of antitumor immunity. Three of 16 patients who were tetramer positive for at least one melanoma antigen (eg, MART-1) pretreatment developed an immune response (IR) to different tumor antigens. Two of 9 patients who were tetramer negative to all melanoma antigens pretreatment developed an IR against gp100. The greatest changes in antitumor immunity occurred at the highest dose levels.

CONCLUSIONS

A dose of aerosolized GM-CSF capable of inducing antitumor immunity in the majority of patients was not reached. All tested doses were well tolerated. The greatest increase in antitumor T cell IRs was achieved at the highest doses of GM-CSF.

Therapy for osteosarcoma: where do we go from here?

Osteosarcoma is the most common malignant primary bone tumor in children and adolescents. Current optimal treatment for osteosarcoma consists of multi-agent chemotherapy and aggressive surgical resection of all sites of disease involvement. The current national and international cooperative trial for patients with newly diagnosed osteosarcoma builds upon the backbone of cisplatin, doxorubicin, and methotrexate. This protocol is designed to clarify whether (i) the addition of ifosfamide and etoposide to postoperative chemotherapy with cisplatin, doxorubicin, and methotrexate improves the event-free survival and overall survival for patients with resectable osteosarcoma and a poor histologic response to 10 weeks of preoperative chemotherapy; and (ii) the addition of pegylated interferon-alpha-2b as maintenance therapy after postoperative chemotherapy with cisplatin, doxorubicin, and methotrexate improves the event-free survival and overall survival for patients with resectable osteosarcoma and a good histologic response to 10 weeks of preoperative chemotherapy. However, the optimal treatment strategy (or strategies) for patients with relapsed or metastatic disease has yet to be defined. This remains one of the persistent challenges in the treatment of osteosarcoma. Recent therapeutic advances have focused on circumventing chemotherapy resistance mechanisms, incorporation of non-classical agents into upfront therapy, targeting of the tumor micro-environment, and investigating the role of novel delivery mechanisms. In patients with localized disease the 5-year survival rate is at least 70%; patients with metastatic or recurrent disease have <20% chance of long-term survival despite aggressive therapies. These figures have changed little in the past 2 decades. This review focuses on the current therapy for osteosarcoma, and highlights emerging strategies that will hopefully change the outlook for patients with this disease.

Translation of new cancer treatments from pet dogs to humans

Naturally occurring cancers in pet dogs and humans share many features, including histological appearance, tumour genetics, molecular targets, biological behaviour and response to conventional therapies. Studying dogs with cancer is likely to provide a valuable perspective that is distinct from that generated by the study of human or rodent cancers alone. The value of this opportunity has been increasingly recognized in the field of cancer research for the identification of cancer-associated genes, the study of environmental risk factors, understanding tumour biology and progression, and, perhaps most importantly, the evaluation and development of novel cancer therapeutics.

Targeted delivery of magnetic aerosol droplets to the lung

The inhalation of medical aerosols is widely used for the treatment of lung disorders such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, respiratory infection and, more recently, lung cancer. Targeted aerosol delivery to the affected lung tissue may improve therapeutic efficiency and minimize unwanted side effects. Despite enormous progress in optimizing aerosol delivery to the lung, targeted aerosol delivery to specific lung regions other than the airways or the lung periphery has not been adequately achieved to date. Here, we show theoretically by computer-aided simulation, and for the first time experimentally in mice, that targeted aerosol delivery to the lung can be achieved with aerosol droplets comprising superparamagnetic iron oxide nanoparticles--so-called nanomagnetosols--in combination with a target-directed magnetic gradient field. We suggest that nanomagnetosols may be useful for treating localized lung disease, by targeting foci of bacterial infection or tumour nodules.

Chemopreventive effect of aerosolized polyphenon E on lung tumorigenesis in A/J mice

Effective chemoprevention of lung cancer in high-risk patients through the administration of pharmacologic or nutritional agents is urgently needed. Aerosol inhalation can deliver chemopreventive agents directly to the respiratory tract to inhibit the tumorigenic process. In this study, polyphenon E (PolyE) and (-)-epigallocatechin-3-gallate (EGCG) were administered by aerosol delivery to A/J mice beginning 2 weeks after carcinogen treatment and continuing daily by inhalation throughout the remainder of the study (20 weeks). PolyE decreased tumor load by approximately 59%. However, EGCG, both at the same dose and at a higher dose, failed to inhibit lung carcinogenesis. These results indicate that aerosol delivery of PolyE, but not EGCG, may be a useful chemopreventive protocol in subjects at high risk for lung cancer.

Effervescent dry powder for respiratory drug delivery

The objective of this work was to develop a new type of respiratory drug delivery carrier particle that incorporates an active release mechanism. Spray drying was used to manufacture inhalable powders containing polybutylcyanoacrylate nanoparticles and ciprofloxacin as model substances for pulmonary delivery. The carrier particles incorporated effervescent technology, thereby adding an active release mechanism to their pulmonary route of administration. Effervescent activity of the carrier particles was observed when the carrier particles were exposed to humidity. Gas bubbles caused by the effervescent reaction were visualized by confocal laser scanning microscopy. The images showed that nanoparticles were distributed throughout the gas bubble. For the effervescent formulation the average mass median aerodynamic diameter (MMAD) was 2.17 microm+/-0.42, fine particle fraction (FPF(<=5.6 microm)) was 46.47%+/-15 and the GSD was 2.00+/-0.06. The results also showed that the effervescent carrier particles released 56+/-8% ciprofloxacin into solution compared with 32+/-3% when lactose carrier particles were used. The mean nanoparticle size did not significantly change upon release when the nanoparticles were incorporated into an effervescent formulation. However, the mean size significantly increased upon release when only lactose was used as carrier particle matrix. In conclusion, effervescent carrier particles can be synthesized with an adequate particle size for deep lung deposition. This opens the door for future research to explore this technology for delivery of a large range of substances to the lungs with possible improved release compared to conventional carrier particles.

Inhaled cytokines and cytokine antagonists

Cytokine and cytokine antagonist have provided novel and effective therapies for many human diseases. A number of approved cytokines including the interferons (alpha, beta and gamma), interleukin-2 (IL-2), granulocyte macrophage colony stimulating factor (GM-CSF) as well as novel cytokine antagonists have been administered by the pulmonary route for both local lung disease and as a non-invasive method for systemic delivery. We review the published clinical experience of inhaled cytokines and cytokine antagonists. We discuss the limitations of the existing data and the type of clinical data desired to establish the advantages and safety of inhaled cytokines and cytokine antagonists.

In vitro assessment of transferrin-conjugated liposomes as drug delivery systems for inhalation therapy of lung cancer

Most human tumours over-express receptors for growth factors and peptide hormones, which are being increasingly studied as a means to selectively deliver cytotoxic agents. An example being the transferrin receptor (TfR, CD71). Here, we studied expression levels and location of TfR in different lung epithelial cell types (i.e., bronchial and alveolar epithelial cells) by flow-cytometry and confocal laser scanning microscopy (CLSM). Furthermore, we assessed uptake levels and cytotoxicity of transferrin (Tf)-conjugated liposomes in vitro. TfR was found to be expressed at a significantly higher level in bronchial epithelial cells compared with their alveolar counterparts. Cells of cancerous origin (i.e., A549 cell line) showed a higher TfR expression level than healthy alveolar epithelial type II cells in primary culture. CLSM revealed TfR to be located primarily at the basolateral aspect of cells, with the exception of cells undergoing mitotic proliferation, which also showed TfR at their apical membranes, due to their loss of cell polarity. Higher expression levels of TfR correlated well with enhanced uptake of Tf-liposomes and increased levels of cytotoxicity. Liposome uptake was temperature-dependent and inhibitable by excess free Tf. Tf-conjugated liposomes appear as good candidates for an approach to deliver cytostatic drugs to sites of lung cancer by inhalation.

The use of amino acids to enhance the aerosolisation of spray-dried powders for pulmonary gene therapy

BACKGROUND

Pulmonary delivery of gene therapy offers the potential for the treatment of a range of lung conditions, including cystic fibrosis, asthma and lung cancer. Spray-drying may be used to prepare dry powders for inhalation; however, aerosolisation of such powders is limited, resulting in poor lung deposition and biological functionality. In this study, we examine the use of amino acids (arginine, aspartic acid, threonine, phenylalanine) to enhance the aerosolisation of spray-dried powders containing model non-viral gene vectors.

METHODS

Lipid/polycation/pDNA (LPD) vectors, in the presence or absence of amino acids, were dispersed in lactose solutions, and spray-dried to produce appropriately sized dry powders. Scanning electron microscopy and laser diffraction were used to determine particle morphology and diameter, respectively. Gel electrophoresis was used to examine the influence of amino acids on the structural integrity of the LPD complex. In vitro cell (A549) transfection was used to determine the biological functionality of the dry powders, and the in vitro aerosolisation performance was assessed using a multistage liquid impinger (MSLI).

RESULTS

Both gel electrophoresis and in vitro cell transfection indicated that certain amino acids (aspartic acid, threonine) can adversely affect the integrity and biological functionality of the LPD complex. All amino acids significantly increased the aerosolisation of the powder, with the arginine and phenylalanine powders showing optimal deposition in the lower stages of the MSLI.

CONCLUSIONS

Amino acids can be used to enhance the aerosolisation of spray-dried powders for respiratory gene delivery, allowing the development of stable and viable formulations for pulmonary gene therapy.

A miniaturized nebulization catheter for improved gene delivery to the mouse lung

BACKGROUND

The available methods for administration of gene delivery systems to the lungs of small animals via nebulization have several drawbacks. These include lack of control over the delivered dose and a negative impact on the stability of the formulation. This paper describes a new nebulization catheter device for the administration of plasmid-based gene delivery systems (polyplexes) as aerosols to the mouse lung in vivo.

METHODS

The physical stability of naked pDNA and polyplexes formulated with chitosan oligomers and PEI was examined following nebulization with the catheter device. We also examined the in vitro transfection efficiency of the polyplexes recovered after nebulization. Lung distribution and gene expression after administration of the selected gene delivery systems to the mouse lung were also investigated.

RESULTS

In contrast to previously described nebulization methods, the structural integrity of the unprotected naked pDNA was maintained following nebulization by the catheter device, which indicates relatively mild nebulization conditions. In addition, the nebulization procedure did not affect the physical stability of the formulated polyplexes. Small volumes of the pDNA aerosol (10-20 microl) were delivered in a highly controlled and reproducible manner. The aerosol droplet size varied with the molecular weight of the polycations. Aerosol delivery via this method resulted in improved lung distribution of pDNA polyplexes and a six-fold increase in the efficiency of gene delivery in vivo over that seen with the commonly used intratracheal instillation method.

CONCLUSION

The use of the nebulization catheter device provides a promising alternative for aerosol gene delivery to the mouse lung.