Effect of arterial administration of high-molecular-weight anticancer agent SMANCS with lipid lymphographic agent on hepatoma: a preliminary report

Embolization alone is as effective as TACE for unresectable HCC: systematic review and meta-analysis of randomized controlled trails

BACKGROUND

Despite transarterial chemoembolization (TACE) was recommended as first line therapy for intermediate hepatocellular carcinoma (HCC), the efficacy of transarterial embolization (TAE) has not been widely recognized. This work was to determine whether TAE was as effective and safe as TACE for unresectable HCC.

METHODS

We performed a systematic search of electronic databases and other sources for randomized controlled studies (RCTs) comparing TAE with TACE for unresectable HCC. Results were expressed as Hazard Ratio (HR) for survival and Odds Ratio (OR) for dichotomous outcomes using RevMan 5.4.1.

RESULTS

We included 6 trials with 683 patients. The risk of bias of included RCTs was from unclear to high risk. There were no significant differences between TACE and TAE for progression-free survival (HR 0.83, 95% CI 0.45-1.55; p = 0.57), overall survival (HR 1.10, 95% CI 0.90-1.35; p = 0.36), and objective response rate (OR 1.17, 95% CI 0.80-1.71; p = 0.42) without obvious publication bias. Sensitivity analyses confirmed the robustness of the results. TAE group reported similar or less adverse effects than TACE group in all the studies.

CONCLUSIONS

Our study demonstrated that TAE was as effective as TACE. Since TAE was simpler, cheaper and had less adverse effects than TACE, TAE should be a better choice in most cases where TACE was indicated for unresectable HCC.

Biological efficacy of simulated radiolabeled Lipiodol® ultra-fluid and microspheres for various beta emitters: study based on VX2 tumors

BACKGROUND

Radioembolization is one therapeutic option for the treatment of locally early-stage hepatocellular carcinoma. The aim of this study was to evaluate the distribution of Lipiodol® ultra-fluid and microspheres and to simulate their effectiveness with different beta emitters (90Y, 188Re, 32P, 166Ho, 131I, and 177Lu) on VX2 tumors implanted in the liver of 30 New Zealand rabbits.

RESULTS

Twenty-three out of 30 rabbits had exploitable data: 14 in the group that received Lipiodol® ultra-fluid (group L), 6 in the group that received microspheres (group M), and 3 in the control group (group C). The histologic analysis showed that the Lipiodol® ultra-fluid distributes homogeneously in the tumor up to 12 days after injection. The X-ray μCT images showed that Lipiodol® ultra-fluid has a more distal penetration in the tumor than microspheres. The entropy (disorder of the system) in the L group was significantly higher than in the M group (4.06 vs 2.67, p = 0.01). Equivalent uniform biological effective doses (EUBED) for a tumor-absorbed dose of 100 Gy were greater in the L group but without statistical significance except for 177Lu (p = 0.03). The radionuclides ranking by EUBED (from high to low) was 90Y, 188Re, 32P, 166Ho, 131I, and 177Lu.

CONCLUSIONS

This study showed a higher ability of Lipiodol® ultra-fluid to penetrate the tumor that translated into a higher EUBED. This study confirms 90Y as a good candidate for radioembolization, although 32P, 166Ho, and 188Re can achieve similar results.

Multidisciplinary Taiwan consensus for the use of conventional TACE in hepatocellular carcinoma treatment

Developed in early 1980s, transarterial chemoembolization (TACE) with Lipiodol was adopted globally after large-scale randomized control trials and meta-analyses proving its effectiveness were completed. Also known as "conventional TACE" (cTACE), TACE is currently the first-line treatment for patients with unresectable intermediate stage hepatocellular carcinoma (HCC) and delivers both ischemic and cytotoxic effects to targeted tumors. Although new technology and clinical studies have contributed to a more comprehensive understanding of when and how to apply this widely-adopted therapeutic modality, some of these new findings and techniques have yet to be incorporated into a guideline appropriate for Taiwan. In addition, differences in the underlying liver pathologies and treatment practices for transcatheter embolization between Taiwan and other Asian or Western populations have not been adequately addressed, with significant variations in the cTACE protocols adopted in different parts of the world. These mainly revolve around the amount and type of chemotherapeutic agents used, the type of embolic materials, reliance on Lipiodol, and the degree of selectiveness in catheter positioning. Subsequently, interpreting and comparing results obtained from different centers in a systematic fashion remain difficult, even for experienced practitioners. To address these concerns, we convened a panel of experts specializing in different aspects of HCC treatment to devise modernized recommendations that reflect recent clinical experiences, as well as cTACE protocols which are tailored for use in Taiwan. The conclusions of this expert panel are described herein.

Selective Enhancing Blood Flow in Solid Tumor Tissue Is the Key for Achieving Satisfactory Delivery and Therapeutic Outcome of Nanodrugs via the EPR Effect

The enhanced permeability and retention effect (EPR effect) is a crucial phenomenon for understanding the pathophysiological characteristics of blood vasculature and microenvironments in solid tumors. It is also an essential concept for designing anticancer drugs that can be selectively delivered into tumor tissue via the unique extravasation and retention mechanism for macromolecular drugs. As tumor vasculature is highly heterogeneous, the intensities of the EPR effect vary according to the types and locations of solid tumors in different species. However, the EPR effect is universally observed in a broad spectrum of solid tumors in human cancer as well as experimental animal tumor models. The matter is how to utilize the EPR effect for drug design and clinical application. Many hypotheses were proposed and tested to enhance the EPR effect in solid tumors in order to increase the efficacy of drug delivery. However, we should focus on increasing the blood flow in tumors so that more drugs can be perfused and accumulated inside tumor tissue and execute anticancer activities. Angiotensin II co-administration and the approach of intratumor arterial infusion should be considered to achieve selective tumor tissue perfusion for nanodrugs.

Interventional oncology of liver tumors: how it all started and where are we now

Liver was the very first organ for which interventional procedures were applied for the local treatment of primary and secondary malignancies. In this paper, the history of Interventional Oncology of liver, from the very beginning to the current situation, is summarized, including both percutaneous and intravascular procedures, and together with the evolution of the techniques for image guidance. The main ongoing developments, such as new techniques, combined interventional treatments and association of local interventions with new drugs are briefly described, too.

35 years of discussions with Prof. Maeda on the EPR effect and future directions

In May 2021, 35 years after first announcing the enhanced permeability and retention (EPR) effect, Dr. Maeda passed away. As a theoretical pillar of high molecular weight drug delivery systems (DDS) with high biocompatibility, the EPR effect has been proven worldwide in experimental mouse models. However, in clinical solid tumors, awareness of the EPR effect is insufficient, and more importantly, DDS has not become the mainstream cancer treatment. Both Dr. Maeda and I were acutely aware of this, and for 35 years, we discussed what to do about it and strived to make up for the inadequacies of the EPR effect by employing different strategies. Dr. Maeda came up with ways to use tumor vascular permeability more effectively and to apply oxidative stress to tumor cells. I proposed cancer stromal targeting (CAST) therapy using the anti-insoluble fibrin antibody conjugated with an anticancer agent in order to overcome the insufficiency of the EPR effect in clinical solid cancers, which possess abundant stromal tissue. Clinical cancers are surrounded by an abundant stroma and survive even under hypoxia and malnutrition due to this stromal barrier. Cancer cells become resistant to any external attack, including with anticancer drugs and radiation. While it goes without saying that EPR effects are important in clinical solid cancer strategies, DDSs that offer both accumulation and even distribution in solid cancers are also required.

Portal Vein Tumor Thrombosis and Hepatocellular Carcinoma - The Changing Tides

Portal vein involvement is considered one of the most fearful complications of hepatocellular carcinoma (HCC). Portal vein tumor thrombosis (PVTT) is associated with aggressive tumor biology (high grade), high tumor burden (number and size of lesions), high levels of serum markers (AFP), poor liver function (deranged LFT), and poor performance status of patients. The Barcelona Clinic Liver Cancer staging system places HCC patients with PVTT in advanced stage (BCLC Stage-C). This group contains a fairly heterogeneous patient population, previously considered candidates for palliative systemic therapy with sorafenib. However, this provided modest overall survival (OS) benefit. The results of a recent Phase III (IMbrave150) trial favor the combination of atezolizumab and bevacizumab over sorafenib as a standard of care in advanced unresectable HCC. While only lenvatinib proved to be non-inferior against sorafenib in a phase III (REFLECT trial), regorafenib (RESORCE trial), ramucirumab (REACH-2), and cabozantinib (CELESTIAL) have been approved second-line therapy in phase III clinical trials. Recently, the data on the prospect of other modalities in the management of HCC with PVTT is mounting with favorable results. Targeting multiple pathways in the HCC cascade using a combination of drugs and other modalities such as RT, TACE, TARE, and HAIC appear effective for systemic and loco-regional control. The quest for the ideal combination therapy and the sequence set is still widely unanswered and prospective trials are lacking. With the armament of available therapeutic options and the advances and refinements in the delivery system, down-staging patients to make them eligible for curative resection has been reported. In a rapidly evolving treatment landscape, performing surgery when appropriate, in the form of LR and even LT to achieve cure does not seem farfetched. Likewise, adjuvant therapy and prompt management of the recurrences holds the key to prolong OS and DFS. This review discusses the management options of HCC patients with PVTT.

The Enhanced Permeability and Retention (EPR) Effect: The Significance of the Concept and Methods to Enhance Its Application

Chemotherapy for human solid tumors in clinical practice is far from satisfactory. Despite the discovery and synthesis of hundreds of thousands of anticancer compounds targeting various crucial units in cancer cell proliferation and metabolism, the fundamental problem is the lack of targeting delivery of these compounds selectively into solid tumor tissue to maintain an effective concentration level for a certain length of time for drug-tumor interaction to execute anticancer activities. The enhanced permeability and retention effect (EPR effect) describes a universal pathophysiological phenomenon and mechanism in which macromolecular compounds such as albumin and other polymer-conjugated drugs beyond certain sizes (above 40 kDa) can progressively accumulate in the tumor vascularized area and thus achieve targeting delivery and retention of anticancer compounds into solid tumor tissue. Targeting therapy via the EPR effect in clinical practice is not always successful since the strength of the EPR effect varies depending on the type and location of tumors, status of blood perfusion in tumors, and the physical-chemical properties of macromolecular anticancer agents. This review highlights the significance of the concept and mechanism of the EPR effect and discusses methods for better utilizing the EPR effect in developing smarter macromolecular nanomedicine to achieve a satisfactory outcome in clinical applications.

Tumor Growth Suppression With Novel Intra-arterial Chemotherapy Using Epirubicin-entrapped Water-in-oil-in-water Emulsion In Vivo

BACKGROUND/AIM

A mixture of anticancer agents and iodized poppy seed oil (IPSO) has been widely used for intra-arterial chemotherapy of hepatocellular carcinoma. However, the anticancer agents can easily separate from IPSO, so the therapeutic potential is limited. We developed epirubicin-entrapped water-in-oil-in-water emulsion (WOW-Epi) using a double-membrane emulsification technique.

MATERIALS AND METHODS

We delivered WOW-Epi through a hepatic arterial injection to VX2 hepatic tumor rabbit model (1.2 mg/kg).

RESULTS

VX2 tumor growth was selectively suppressed in the WOW-Epi-treated group compared with the control treated groups. The accumulation of WOW in nearby cancer cells was confirmed via electron-microscopy. Endocytosis seemed to be the mechanism underlying the uptake of WOW.

CONCLUSION

WOW-Epi led to tumour growth suppression in vivo. WOW does not cause toxicity to arterial vessels. WOW-Epi will be hopefully used for repeated intra-arterial chemotherapy to HCC patients in the near future.

The 35th Anniversary of the Discovery of EPR Effect: A New Wave of Nanomedicines for Tumor-Targeted Drug Delivery-Personal Remarks and Future Prospects

This Special Issue on the enhanced permeability and retention (EPR) effect commemorates the 35th anniversary of its discovery, the original 1986 Matsumura and Maeda finding being published in Cancer Research as a new concept in cancer chemotherapy. My review here describes the history and heterogeneity of the EPR effect, which involves defective tumor blood vessels and blood flow. We reported that restoring obstructed tumor blood flow overcomes impaired drug delivery, leading to improved EPR effects. I also discuss gaps between small animal cancers used in experimental models and large clinical cancers in humans, which usually involve heterogeneous EPR effects, vascular abnormalities in multiple necrotic foci, and tumor emboli. Here, I emphasize arterial infusion of oily formulations of nanodrugs into tumor-feeding arteries, which is the most tumor-selective drug delivery method, with tumor/blood ratios of 100-fold. This method is literally the most personalized medicine because arterial infusions differ for each patient, and drug doses infused depend on tumor size and anatomy in each patient. Future developments in EPR effect-based treatment will range from chemotherapy to photodynamic therapy, boron neutron capture therapy, and therapies for free radical diseases. This review focuses on our own work, which stimulated numerous scientists to perform research in nanotechnology and drug delivery systems, thereby spawning a new cancer treatment era.

Factors affecting the dynamics and heterogeneity of the EPR effect: pathophysiological and pathoanatomic features, drug formulations and physicochemical factors

INTRODUCTION

The enhanced permeability and retention (EPR) effect serves as the foundation of anticancer nanomedicine design. EPR effect-based drug delivery is an effective strategy for most solid tumors. However, the degree of efficacy depends on the pathophysiological conditions of tumors, drug formulations, and other factors.

AREAS COVERED

Vascular mediators including nitric oxide, bradykinin , and prostaglandins are vital for facilitating and maintaining EPR effect dynamics. Progression to large, advanced cancers may induce activated blood coagulation cascades, which lead to thrombus formation in tumor vasculature. Rapidly growing tumors cause obstructed or suppressed blood flow in tumor vasculature related to embolism or occluded blood vessels. The resulting limited tumor blood flow leads to less drug delivered to tumors, i.e. no or poor EPR effect. High stromal content also suppresses vascular permeability and drug diffusion. Restoring obstructed tumor blood flow and improving tumor vascular permeability via vascular mediators will improve drug delivery and the EPR effect. Physicochemical features of nanomedicines also influence therapeutic outcomes and are vital for the EPR effect.

EXPERT OPINION

The tumor microenvironment, especially tumor blood flow, is critical for a potent EPR effect. A rational strategy for circumventing EPR effect barriers must include restoring tumor blood flow.

Efficacy and Safety of Supplemental Transarterial Chemoembolization Through Extrahepatic Collateral Arteries with Drug-eluting Beads: Treatment for Unresectable Hepatocellular Carcinoma

Purpose

To evaluate the therapeutic efficacy and safety of supplement transarterial chemoembolization (TACE) with drug-eluting beads TACE (DEB-TACE) through extrahepatic collateral (EHC) arteries for the treatment of hepatocellular carcinoma (HCC).

Patients and Methods

In this retrospective study, 61 unresectable HCC patients with treatment-naïve EHC blood supplies who received TACE from January 2016 to March 2019 were enrolled; of these patients, 42 (68.9%) received DEB-TACE, and 19 (31.1%) received cTACE. The hepatic tumor feeding arteries were treated in the same TACE session if it presented. The tumor response, time-to-progression (TTP), and overall survival (OS) were analyzed. Safety was assessed based on the occurrence of liver function deterioration and major complications within three months after TACE.

Results

DEB-TACE showed better efficacy than cTACE in the disease control rate (p=0.001), overall response rate (p=0.005), the TTP (eight months vsthree months, p=0.002) and the OS (23.8 months vs nine months, p=0.045). Nine patients in the DEB-TACE group and one patient in the cTACE group were downstaged to resection or liver transplantation (21.4% vs 5.3%, p=0.151). DEB-TACE and cTACE have no difference in the acute and chronic liver toxicity. With regard to complications, there was no significant difference in the occurrence of both major (16.7% vs 21.1%, p=0.72) and minor (57.1% vs 47.4%, p=0.48) complications between DEB-TACE and cTACE.

Conclusion

DEB-TACE through EHC arteries has a potential therapeutic effect in the treatment of unresectable HCC, with comparable safety compared with cTACE.

Transarterial chemoembolization for hepatocellular carcinoma: a bibliometric analysis of the most cited articles

PURPOSE

Bibliometric analysis is a quantitative assessment of the academic literature in a particular field. The aim of our study was to characterize the 100 top-cited articles regarding transarterial chemoembolization (TACE) for the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

The 'Web of Science' database was used to identify the leading articles regarding TACE for HCC. We determined the top 100 articles according to citations and performed an analysis on year of publication, authorship, department affiliation, publishing journal, institution and country of origin, subject matter and article type.

RESULTS

The top-cited articles received between 92 and 2254 citations (median 283.4). The top 100 papers were published in 32 journals between 1983 and 2016. Cancer, Radiology and Hepatology published the most articles (n = 40). Internal medicine was the department affiliation of the first author in 49%. The country providing the most highly cited articles was Japan (n = 24).

CONCLUSION

We performed an analysis of the 100 top-cited articles dealing with TACE for HCC, presenting a detailed list of the most influential and historically significant papers. Japan was the country that produced the most top-cited articles, highlighting its key contribution to this field of the literature.

Clinical Pharmacokinetics and Pharmacodynamics of Transarterial Chemoembolization and Targeted Therapies in Hepatocellular Carcinoma

The management of hepatocellular carcinoma (HCC) is based on a multidisciplinary decision tree. Treatment includes loco-regional therapy, mainly transarterial chemoembolization, for intermediate-stage HCC and systemic therapy with oral tyrosine kinase inhibitors (TKIs) for advanced HCC. Transarterial chemoembolization involves hepatic intra-arterial infusion with either conventional procedure or drug-eluting-beads. The aim of the loco-regional procedure is to deliver treatment as close as possible to the tumor both to embolize the tumor area and to enhance efficacy and minimize systemic toxicity of the anticancer drug. Pharmacokinetic studies applied to transarterial chemoembolization are rare and pharmacodynamic studies even rarer. However, all available studies lead to the same conclusions: use of the transarterial route lowers systemic exposure to the cytotoxic drug and leads to much higher tumor drug concentrations than does a similar dose via the intravenous route. However, reproducibility of the procedure remains a major problem, and no consensus exists regarding the choice of anticancer drug and its dosage. Systemic therapy with TKIs is based on sorafenib and lenvatinib as first-line treatment and regorafenib and cabozantinib as second-line treatment. Clinical use of TKIs is challenging because of their complex pharmacokinetics, with high liver metabolism yielding both active metabolites and their common toxicities. Changes in liver function over time with the progression of HCC adds further complexity to the use of TKIs. The challenges posed by TKIs and the HCC disease process means monitoring of TKIs is required to improve clinical management. To date, only partial data supporting sorafenib monitoring is available. Results from further pharmacokinetic/pharmacodynamic studies of these four TKIs are eagerly awaited and are expected to permit such monitoring and the development of consensus guidelines.

Multi-energy computed tomography and material quantification: Current barriers and opportunities for advancement

Computed tomography (CT) technology has rapidly evolved since its introduction in the 1970s. It is a highly important diagnostic tool for clinicians as demonstrated by the significant increase in utilization over several decades. However, much of the effort to develop and advance CT applications has been focused on improving visual sensitivity and reducing radiation dose. In comparison to these areas, improvements in quantitative CT have lagged behind. While this could be a consequence of the technological limitations of conventional CT, advanced dual-energy CT (DECT) and photon-counting detector CT (PCD-CT) offer new opportunities for quantitation. Routine use of DECT is becoming more widely available and PCD-CT is rapidly developing. This review covers efforts to address an unmet need for improved quantitative imaging to better characterize disease, identify biomarkers, and evaluate therapeutic response, with an emphasis on multi-energy CT applications. The review will primarily discuss applications that have utilized quantitative metrics using both conventional and DECT, such as bone mineral density measurement, evaluation of renal lesions, and diagnosis of fatty liver disease. Other topics that will be discussed include efforts to improve quantitative CT volumetry and radiomics. Finally, we will address the use of quantitative CT to enhance image-guided techniques for surgery, radiotherapy and interventions and provide unique opportunities for development of new contrast agents.

Nanomedicine as a putative approach for active targeting of hepatocellular carcinoma

The effectiveness of chemotherapy in hepatocellular carcinoma (HCC) is restricted by chemo-resistance and systemic side effects. To improve the efficacy and safety of chemotherapeutics in HCC management, scientists have attempted to deliver these drugs to malignant tissues using targeted carriers as nanoparticles (NPs). Among the three types of NPs targeting (active, passive, and stimuli-responsive), active targeting is the most commonly investigated in HCC treatment. Despite the observed promising results so far, clinical research on nanomedicine targeting for HCC treatment still faces many challenges.These include batch-to-batch physicochemical properties' variations, limiting large scale production and insufficient data on human and environmental toxicities. This review summarized the characteristics of different nanocarriers, ligands, targeted receptors on HCC cells and provided recommendations to overcome the challenges, facing this novel line of treatment for HCC.

Nitroglycerine use in transcatheter arterial (chemo) embolization in patients with hepatocellular carcinoma: Five-year retrospective study

BACKGROUND

Addition of nitroglycerine (NTG) to transcatheter arterial embolization/transarterial chemoembolization (TAE/TACE) has been shown to increase deposition of Lipiodol emulsion in hepatocellular carcinoma (HCC) tumors. The aim of this retrospective study was to evaluate if the addition of nitroglycerin (NTG) to TAE/TACE improved treatment response in HCC.

METHODS

Patients with HCC either received (n=42) or did not receive (non-NTG) (n=111) NTG and an emulsion of Lipiodol with or without doxorubicin, followed by embolization with Gelfoam pledgets. Treatment response was monitored using dual-energy computer tomography (CT). Disease progression and overall survival (OS) were monitored.

RESULTS

The rate of disease progression in the NTG group was 86.5% and in the non-NTG group was 88.6%. Median time to disease progression was 12 months (95% CI; 9.0, 15.0) for the NTG group and 12 months (95% CI; 10.4, 13.6) for the non-NTG groups (P=0.040). No difference was observed in OS between the NTG (60 months) and the non-NTG groups (41 months) (P=0.117). Multivariate analysis found that in the NTG group, OS was associated with Cancer of the Liver Italian Program (CLIP) stage I and Barcelona Clinic Liver Cancer (BCLC) stage B.

CONCLUSIONS

Addition of NTG to TAE/TACE did not result in improved OS or disease progression.

Five-year outcome of conventional and drug-eluting transcatheter arterial chemoembolization in patients with hepatocellular carcinoma

Background

Currently, no standard of care or therapies have been established for patients with advanced HCC. We evaluated the efficacy and safety of conventional transarterial chemoembolization using gelatin sponges or microspheres plus lipiodol-doxorubicin (cTACE) and TACE with doxorubicin-loaded drug eluting beads (DEB-TACE).

Methods

This retrospective study included 273 patients who received cTACE (n = 201) or DEB-TACE. Tumor response, survival, and adverse events were evaluated over a 5-year follow-up period.

Results

During 5-year follow-up, a greater percentage of patients treated with cTACE died than those treated with DEB-TACE (76.1% vs. 66.7%) (P = 0.045). At the last evaluation, all surviving patients had disease progression and no differences were seen between treatment groups. However, the time to disease progression differed between groups; median time to disease progression was 11.0 months for cTACE and 16.0 months for DEB-TACE (P = 0.019). The median survival time was 37 months in both treatment groups. No significant differences were observed between cTACE and DEB-TACE therapies in subgroups of patients with BCLC stage A or stage B + C either in survival time or time to disease progression (P values > 0.05). No significant differences were observed in survival status or disease progression between cTACE and DEB-TACE in patient subgroups with either tumor number > 5 or with the sum of the diameter of largest five HCC tumors being > 7 cm.

Conclusions

DEB-TACE demonstrates greater long-term benefits than cTACE in treating treatment-naïve patients with HCC. Results of this long-term study support the use of DEB-TACE in treating HCC.

Liver chemoembolization of hepatocellular carcinoma using TANDEM® microspheres

Transarterial chemoembolization (TACE) combines intra-arterial delivery of a chemotherapeutic agent with selective embolization to obtain a synergistic effect. TACE is recognized as the standard treatment of hepatocellular carcinoma patients at an intermediate stage. If conventional TACE, defined as the injection of an emulsion of a drug with ethiodized oil, still has a role to play, the development of drug-eluting beads has allowed many improvements and optimization of the technique. TANDEM^® microspheres are second-generation drug-loadable microspheres. This device raised a special interest due to its tightly calibrated spherical microspheres, with small sizes down to 40 μm available. In this review, we describe the technical characteristics of these microspheres, analyze the scientific literature and hypothesize on the future perspectives.

Medical Treatment of Hepatocellular Carcinoma: Any Progress?

Background

Hepatocellular carcinoma (HCC) remains one of the most common neoplasms worldwide. Curative treatment options include liver transplantation or resection. Unfortunately, most patients still have unresectable or untransplantable HCC due to disease extension or comorbid factors and are therefore candidate only for palliative treatments.

Methods

In this review we have analyzed the different medical approaches employed in the treatment of HCC in an attempt to better define their roles.

Results

Palliative medical treatments including systemic chemotherapy, immunotherapy or hormonal manipulation rarely influence survival of the patients. Although a high response rate is often reported with new local therapies such as transcatheter arterial embolization, intraarterial chemotherapy or percutaneous ethanol injection, the real impact of these treatment modalities on patient survival remains to be determined.

Conclusion

One way to improve the diagnosis of HCC patients would be an appropriate approach to evaluate new drugs or treatment modalities. To answer all the open questions, further trials, possibly randomized, should be conducted on a substantial number of patients with homogeneous prognostic factors.

Conjugate Polyplexes with Anti-Invasive Properties and Improved siRNA Delivery In Vivo

This study reports on a simple method to prepare siRNA-polycation conjugate polyplexes by in situ thiol-disulfide exchange reaction. The conjugate polyplexes are prepared using thiol-terminated siRNA and a bioreducible branched polycationic inhibitor of the CXCR4 chemokine receptor (rPAMD). The rPAMD-SS-siRNA conjugate polyplexes exhibit improved colloidal stability and resistance against disassembly with heparin, serum, and physiological salt concentrations when compared with control conventional rPAMD/siRNA polyplexes. Coating the polyplexes with human serum albumin masks the positive surface charge and contributes to the enhanced in vitro gene silencing and improved safety in vivo. The conjugate polyplexes display improved in vivo reporter gene silencing following intravenous injection in tumor-bearing mice. Because the conjugate polyplexes retained the ability of rPAMD to inhibit CXCR4 and restrict cancer cell invasion, the developed systems show promise for future combination anti-metastatic siRNA therapies of cancer.

New molecular targets for functionalized nanosized drug delivery systems in personalized therapy for hepatocellular carcinoma

Hepatocellular carcinoma, the most frequent solid tumor of the liver, has a very poor prognosis, being the second most common cause of death from cancer worldwide. The incidence and mortality of this liver tumor are increasing in most areas of the world as a consequence of aging and the emerging of new risk factors such as the metabolic syndrome, beside the recognized role of hepatitis B and C viral infections and alcohol abuse. Despite the increasing knowledge on the molecular mechanisms underlying hepatic carcinogenesis, effective therapeutic strategies are still an unmet clinical need. Efforts have been made to develop selective drugs as well as effective targeted drug delivery systems. The development of novel drug carriers for therapeutic molecules can indeed offer a valuable strategy to ameliorate the efficacy of HCC treatment. In this review, we discuss recent drug delivery strategies for HCC treatment based on the exploitation of targeted nanoparticles (NPs). Indeed, a few of these platforms have achieved an advanced stage of preclinical development. Here, we review the most promising drug nanovehicles based on both synthetic and natural polymers, including polysaccharides that have emerged for their biocompatibility and biodegradability. To maximize site-selectivity and therapeutic efficacy, drug delivery systems should be functionalized with ligands which can specifically recognize and bind targets expressed by HCC, namely cell membrane associated antigens, receptors or biotransporters. Cell surface and intracellular molecular targets are exploited either to selectively deliver drug-loaded nanovehicles or to design novel selective therapeutics. In conclusion, the combination of novel and safe drug delivery strategies based on site-specific targeted drug nanovehicles with therapeutic molecular targets may significantly improve the pharmacological efficacy for the treatment of HCC.

Nanomedicine for prostate cancer using nanoemulsion: A review

Prostate cancer (PCa) is a worldwide issue, with burgeoning rise in prevalence, morbidity and mortality. Targeted drug delivery, a long sort solution in this regard using controlled release (CR) - nanocarriers, is still a challenge. There is an emerging criticism that, the challenges are due to less appreciation for the biological barriers and lack of corresponding newer technologies. Over the years, more understanding about the biological barriers has come with the progress in characterization techniques. Correspondingly, there is a change in opinion about approaches in clinical trial that; focus of the end point need to be shifted towards disease stabilization for these explorative technologies. Currently, there is a requirement to overcome these newly identified challenges to develop newer affordable therapeutics. The ongoing clinical protocol for therapy using CR-nanocarriers is intravenous injection followed by local targeting to cancer site. This is the most accepted protocol and new CR-nanocarriers are being developed to suit this protocol. In this review, recent progress in treatment of PCa using CR-nanocarriers is analyzed with respect to newly identified biological barriers and design challenges. Possibilities of exploring nanoemulsion (NE) platform for targeted drug delivery to PCa are examined. Repurposing of drugs and combination therapy using NE platform targeted to PCa can be explored for design and development of affordable nanomedicine. In 20yrs. from now there expected to be numerous affordable nanomedicine technologies available in market exploring these lines.

Selective boron delivery by intra-arterial injection of BSH-WOW emulsion in hepatic cancer model for neutron capture therapy

OBJECTIVE

Boron neutron-capture therapy (BNCT) has been used to inhibit the growth of various types of cancers. In this study, we developed a ¹⁰BSH-entrapped water-in-oil-in-water (WOW) emulsion, evaluated it as a selective boron carrier for the possible application of BNCT in hepatocellular carcinoma treatment.

METHODS

We prepared the ¹⁰BSH-entrapped WOW emulsion using double emulsification technique and then evaluated the delivery efficacy by performing biodistribution experiment on VX-2 rabbit hepatic tumour model with comparison to iodized poppy-seed oil mix conventional emulsion. Neutron irradiation was carried out at Kyoto University Research Reactor with an average thermal neutron fluence of 5 × 10¹² n cm^-2. Morphological and pathological analyses were performed on Day 14 after neutron irradiation.

RESULTS

Biodistribution results have revealed that ¹⁰B atoms delivery with WOW emulsion was superior compared with those using iodized poppy-seed oil conventional emulsion. There was no dissemination in abdomen or lung metastasis observed after neutron irradiation in the groups treated with ¹⁰BSH-entrapped WOW emulsion, whereas many tumour nodules were recognized in the liver, abdominal cavity, peritoneum and bilateral lobes of the lung in the non-injected group.

CONCLUSION

Tumour growth suppression and cancer-cell-killing effect was observed from the morphological and pathological analyses of the ¹⁰BSH-entrapped WOW emulsion-injected group, indicating its feasibility to be applied as a novel intra-arterial boron carrier for BNCT. Advances in knowledge: The results of the current study have shown that entrapped ¹⁰BSH has the potential to increase the range of therapies available for hepatocellular carcinoma which is considered to be one of the most difficult tumours to cure.

New concepts in embolotherapy of HCC

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related deaths worldwide with rapidly growing incidence rates in the USA and Europe. Despite improving surveillance programs, most patients are diagnosed at intermediate to advanced stages and are no longer amenable to curative therapies, such as ablation, surgical resection and liver transplantation. For such patients, catheter-based image-guided embolotherapies such as transarterial chemoembolization (TACE) represent the standard of care and mainstay therapy, as recommended and endorsed by a variety of national guidelines and staging systems. The main benefit of these therapies is explained by the preferentially arterial blood supply of liver tumors, which allows to deliver the anticancer therapy directly to the tumor-feeding artery while sparing the healthy hepatic tissue mainly supplied by the portal vein. The tool box of an interventional oncologist contains several different variants of transarterial treatment modalities. Ever since the first TACE more than 30 years ago, these techniques have been progressively refined, both with respect to drug delivery materials and with respect to angiographic micro-catheter and image-guidance technology, thus substantially improving therapeutic outcomes of HCC. This review will summarize the fundamental principles, technical and clinical data on the application of different embolotherapies, such as bland transarterial embolization, Lipiodol-based conventional transarterial chemoembolization as well as TACE with drug-eluting beads (DEB-TACE). Clinical data on ⁹⁰Yttrium radioembolization as an emerging alternative, mostly applied for niche indications such as HCC with portal vein invasion, will be discussed. Furthermore, we will summarize the principle of HCC staging, patient allocation and response assessment in the setting of HCC embolotherapy. In addition, we will evaluate the role of cone-beam computed tomography as a novel intra-procedural image-guidance technology. Finally, this review will touch on new technical developments such as radiopaque, imageable DEBs and the rationale and role of combined systemic and locoregional therapies, mostly in combination with Sorafenib.

The value of paradoxical uptake of hepatocellular carcinoma on the hepatobiliary phase of gadoxetic acid-enhanced liver magnetic resonance imaging for the prediction of lipiodol uptake after transcatheter arterial chemoembolization

PURPOSE

To compare the response to transcatheter arterial chemoembolization (TACE) between hepatocellular carcinoma (HCC) with paradoxical uptake on the hepatobiliary phase (HBP) (HCC_para) and HCC with defect on the HBP (HCC_def), and to identify some imaging features that can differentiate between two groups.

MATERIALS AND METHODS

Ninety-three HCCs from 54 patients who underwent gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) prior to TACE were included. HCCs were classified into two groups according to the signal intensity (SI) on the HBP: HCC_para and HCC_def. Using post-TACE computed tomography (CT) as a reference standard, initial compact lipiodol uptake was assessed and compared between groups. The arterial enhancement ratio (AER), SI ratios of the arterial phase and HBP, and presence of the capsule appearance were compared between groups. After initial response, local tumor recurrence within 6 and 18 months was evaluated based on follow-up CT or MRI.

RESULTS

Fifteen HCC_para and 78 HCC_def were included. Compared to HCC_def, HCC_para showed more frequent initial compact lipiodol uptake (p=0.009), larger mean size (p=0.019), lower AER (p=0.005), higher SI ratio of the HBP (p<0.0001), and more frequent capsule appearance (p<0.0001). Local tumor recurrence rate within 6 months was also significantly lower in HCC_para than in HCC_def (p=0.008).

CONCLUSION

Despite larger size and lower AER, HCC_para showed more frequent initial compact lipiodol uptake and lower early local recurrence rate after TACE than did HCC_def.

A Retrospective 30 Years After Discovery of the Enhanced Permeability and Retention Effect of Solid Tumors: Next-Generation Chemotherapeutics and Photodynamic Therapy--Problems, Solutions, and Prospects

Solid tumor has unique vascular architecture, excessive production of vascular mediators, and extravasation of macromolecules from blood vessels into the tumor tissue interstitium. These features comprise the phenomenon named the EPR effect of solid tumors, described in 1986. Our investigations on the EPR revealed that many mediators, such as bradykinin, NO, and prostaglandins, are involved in the EPR effect, which is now believed to be the most important element for cancer-selective drug delivery. However, tumors in vivo manifest great diversity, and some demonstrate a poor EPR effect, for example, because of impaired vascular flow involving thrombosis, with poor drug delivery and therapeutic failure. Another important element of this effect is that it operates in metastatic cancers. Because few drugs are currently effective against metastases, the EPR effect offers a great advantage in nanomedicine therapy. The EPR effect can also be augmented two to three times via nitroglycerin, ACE inhibitors, and angiotensin II-induced hypertension. The delivery of nanomedicines to tumors can thereby be enhanced. In traditional PDT, most PSs had low MW and little tumor-selective accumulation. Our hydroxypropylmetacrylamide-polymer-conjugated-PS, zinc protoporphyrin (apparent MW >50 kDa) showed tumor-selective accumulation, as revealed by fluorescent imaging of autochthonous cancers. After one i.v. injection of polymeric PS followed by two or three xenon light irradiation/treatments, most tumors regressed. Thus, nanoprobes with the EPR effect seem to have remarkable effects. Enhancing the EPR effect by using vascular modulators will aid innovations in PDT for greater tumor-targeted drug delivery.

Interventional oncology for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and is increasing in incidence. The overall prognosis of patients with liver cancer is poor. The Barcelona Clinic Liver Cancer (BCLC) classification in 5 stages is endorsed by European Association for the Study of the Liver (EASL) and American Association for the Study of Liver Disease (AASLD). This classification is recommended for treatment allocation. Because a small proportion of patients are suitable for curative surgical treatment, various locoregional therapies are widely used to manage patients with HCC. The image-guided therapies, also called interventional radiology or interventional oncology (IO) techniques consisted in percutaneous or endovascular approach. This article reviews the different IO treatments available in HCC patients and the strength of the data.

Synthesis and Biological Evaluation of Peg-Substituted Macromolecular Prodrugs of Mitomycin C

Poly(ethylene glycol) (PEG)-substituted macromolecular mitomycin C (MMC)-derivatives were synthetized using poly[N5-(2-hydroxyethyl)-L-glutamine] as the polymeric backbone. As an oligopeptide spacer between the drug and the polymer, tetrapeptide gly-phe-ala-leu was selected. To study the influence of PEG side groups on the antitumor activity of the derivatives, the conjugates were evaluated biologically in vitro and in vivo. The in vitro experiments showed only a minor influence of the PEGside groups on the antitumor activity. The results of the in vivo experiments on mice with a human type tumor were promising. Some derivatives lead to a remarkable tumor size regression. Furthermore, in vivo treatment of tumor bearing mice with the macromolecular MMC derivatives resulted in significantly longer survival times compared to free MMC.

Prognostic Factors in Liver Metastases after Transcatheter Arterial Embolization or Arterial Infusion

From January 1986 to December 1988, 85 patients (55 men and 30 women, mean age 59 years) with metastatic liver tumors were treated with hepatic artery embolization (TAE) or infusion (HAI). Sixty-eight patients with successful catheterization were treated with TAE using iodized oil (Lipiodol) mixed with anticancer agent (ACA). In 12 of 68 patients with hypervascular tumors gelatin sponge was added. Patients with unsuccessful catheterization were treated with hepatic artery infusion of ACA. Forty-three patients received oral chemotherapy following TAE or HAI. Overall, the 6-month, and 1- and 2-year survival rates were 69.5, 31.8 and 4.1 per cent, respectively (mean 233 days). A univariate analysis of prognostic factors showed that number of metastases, stage, treatment times and oral chemotherapy were all significant factors (p<0.05). Ascites, jaundice, percentage of hepatic replacement and treatment protocol also had some influence (p<0.1). Sex, age, primary site, elevation of tumor markers, other metastatic lesions, portal vein involvement and difference in anticancer agent had no prognostic significance. A multivariate analysis using Cox's proportional hazard model revealed that the number of treatments had the most important prognostic significance, followed by oral chemotherapy, stage and percentage of hepatic replacement.

Transcatheter Arterial Chemotherapy Using Doxorubicin, Iodized Oil and Gelfoam Embolization in Hepatocellular Carcinoma

Computed tomography (CT) was performed in 54 patients with hepatocellular carcinoma three weeks after transcatheter arterial chemotherapy using iodized oil and doxorubicin with or without gelfoam embolization. Patients with iodized oil retention in the tumor greater than 50 per cent of tumor size survived longer than patients with retention of less than 50 per cent. Differences were also found within Okuda stages I and II, but they were significant only in Okuda stage I (p<0.0001). These results suggest a possible relationship between iodized oil retention and survival. In addition to Okuda stage, several factors affected iodized oil retention: tumor vascularity, tumor size, portal thrombosis and Gelfoam embolization. These factors may thus influence the prognosis after transcatheter arterial chemotherapy.

Treatment of Hepatocellular Carcinoma by Intraarterial Injection of Adriamycin/Mitomycin C Oil Suspension (ADMOS) Alone or Combined with CIS-Diaminodichloroplatinum (CDDP)

We evaluated the effects of intraarterial injection of Adriamycin/Mitomycin C oil (Lipiodol) suspension (ADMOS) alone and ADMOS + cis-diaminodichloroplatinum (CDDP) in 135 patients with hepatocellular carcinoma (HCC). A total of 59 patients received ADMOS alone and 76 patients received ADMOS + CDDP (ADMOS/CDDP). Tumor size was reduced by over 25% in 13 (34%) of the evaluable 38 patients in the ADMOS-alone group and in 39 (51%) of the 76 evaluable patients in the ADMOS/CDDP group. Serum alpha-fetoprotein (AFP) levels decreased by more than 50% in 10 (59%) of 17 ADMOS-alone patients and in 23 (70%) of 33 ADMOS/CDDP patients whose pretreatment AFP levels were above 0.2 mg/l. The overall one- and 2-year survival rates were 68% and 41%, respectively. No severe complications and no significant changes in laboratory values were observed, except for one patient in the ADMOS/CDDP group who developed a liver abscess. Although the tumor response was significantly better in patients treated by ADMOS/CDDP than in those treated by ADMOS-alone (p < 0.05), there was no significant difference in the survival rates between the 2 groups. The intraarterial injection of ADMOS and CDDP was concluded to be effective in treating HCC judging by tumor response.

Intra-Arterial Injection of Adriamycin/Mitomycin C Lipiodol Suspension in Liver Metastases

Intra-arterial injection of a suspension of adriamycin and/or mitomycin C in Lipiodol was performed in 17 patients with hepatic metastases, which at angiography were poorly vascularized. Accumulation of Lipiodol in the tumors was demonstrated at computed tomography (CT) in 15 of 17 patients examined within one week. Follow-up with CT showed that Lipiodol remained in the tumor during the first month in 94 per cent, after 2 months in 31 per cent, and after 3 months in 17 per cent. In the non-tumor part of the liver Lipiodol disappeared earlier, and one month after injection it could no longer be traced on CT. In 8/17 cases (47%) CT, after intra-arterial injection of Lipiodol, gave superior information compared with CT after intravenous contrast enhancement. Tumor response was achieved in 9 of 16 cases. Particularly in metastases originating from cancer of the colon and stomach response was observed with a decrease in tumor size in 8 of 10 patients.

Treatment of Liver Metastases by Arterial Injection of Adriamycin/Mitomycin C Lipiodol Suspension

Sixty-one patients with liver metastases were treated with hepatic arterial injection of Adriamycin/Mitomycin C oil suspension (ADMOS). The liver metastases originated from the gastrointestinal tract in 41 patients and from other organs in 20 patients. Sixty-nine liver tumors were analyzed in these 61 patients. Computed tomography (CT) after ADMOS injection (Lip-CT) gave more information in 19 cases (31%) than enhanced CT with a water-soluble contrast medium. With Lip-CT, Lipiodol tumor enhancement was observed in 64 of 69 lesions. The patterns of Lipiodol uptake in the tumors were classified into 4 types: Homogeneous accumulation (20%), heterogeneous accumulation (16%); accumulation with a central defect (57%); and no accumulation (7%). A tumor response was achieved in 41 of 69 lesions (59%). Anticancer effects were also shown as a decrease in serum CEA levels. The one year survival rate estimated by the Kaplan-Meier method was 43 per cent and the median survival time was 337 days. The results were better among patients who received multiple doses of ADMOS. Only minimal side effects were associated with ADMOS. The method is considered to be an excellent diagnostic and therapeutic procedure for liver metastases.

Polymer Drugs and Polymeric Drugs, Part VII*: Antitumor Conjugated Polymeric Drugs Consisting of 5-Fluorouracil and Polyanionic Polymers

Derivatives of 5-flurorouracil 1-N-p-vinylbenzoyl-5-fluorouracil (VBFU) were prepared and the solvolysis rates were determined and compared with other 1-N-substituted 5-fluorouracils. VBFU was homopolymerized and copolymerized with maleic anhydride or poly(ethylene glycol) macromonomer. The hydrolysis of these polymeric drugs was studied in a phosphate buffer solu tion, and in vivo antitumor activity was evaluated using Ehrlich's ascites or Sarcoma 180 tumor-bearing mice.

Transcatheter intra-arterial infusion of doxorubicin loaded porous magnetic nano-clusters with iodinated oil for the treatment of liver cancer

A promising strategy for liver cancer treatment is to deliver chemotherapeutic agents with multifunctional carriers into the tumor tissue via intra-arterial (IA) transcatheter infusion. These carriers should release drugs within the target tissue for prolonged periods and permit intra-procedural multi-modal imaging of selective tumor delivery. This targeted transcatheter delivery approach is enabled via the arterial blood supply to liver tumors and utilized in current clinical practice which is called chemoembolization or radioembolization. During our study, we developed Doxorubicin (Dox) loaded porous magnetic nano-clusters (Dox-pMNCs). The porous structure and carboxylic groups on the MNCs achieved high-drug loading efficiency and sustained drug release, along with magnetic properties resulting in high MRI T2-weighted image contrast. Dox-pMNC within iodinated oil, Dox-pMNCs, and Dox within iodinated oil were infused via hepatic arteries to target liver tumors in a rabbit model. MRI and histological evaluations revealed that the long-term drug release and retention of Dox-pMNCs within iodinated oil induced significantly enhanced liver cancer cell death.

Lipopolyplex for Therapeutic Gene Delivery and Its Application for the Treatment of Parkinson's Disease

Lipopolyplex is a core-shell structure composed of nucleic acid, polycation and lipid. As a non-viral gene delivery vector, lipopolyplex combining the advantages of polyplex and lipoplex has shown superior colloidal stability, reduced cytotoxicity, extremely high gene transfection efficiency. Following intravenous administration, there are many strategies based on lipopolyplex to overcome the complex biological barriers in systemic gene delivery including condensation of nucleic acids into nanoparticles, long circulation, cell targeting, endosomal escape, release to cytoplasm and entry into cell nucleus. Parkinson's disease (PD) is the second most common neurodegenerative disorder and severely influences the patients' life quality. Current gene therapy clinical trials for PD employing viral vectors didn't achieve satisfactory efficacy. However, lipopolyplex may become a promising alternative approach owing to its stability in blood, ability to cross the blood-brain barrier (BBB) and specific targeting to diseased brain cells.

Advances in transarterial therapies for hepatocellular carcinoma: is novel technology leading to better outcomes?

Conventional transarterial chemoembolization (c-TACE) was validated in 2002 for intermediate stage hepatocellular carcinoma (HCC). Recent improvements in overall survival after c-TACE in HCC is linked to both better patient selection, and improvement in treatment technologies: catheter, image guidance and new drug delivery platforms. Drug eluting beads (DEBs) demonstrated a benefit over c-TACE in pharmacokinetic studies; however, two randomized studies comparing c-TACE and DEB-TACE demonstrated no benefit of DEB-TACE in response rate or overall survival. Delivery platforms loaded with yttrium-90 deliver selective internal radiation therapy, which opens a new field of therapy for HCC. Future improvement in intra-arterial therapies will include resorbable loadable embolic material, new emulsion used for c-TACE and platforms releasing multikinase inhibitors.

A multifunctional contrast dye for morphological research

OBJECTIVES

We sought to devise and test a multifunctional contrast dye agent for X-ray based digital radiography (DR) or computer tomography (CT), magnetic resonance imaging (MRI), and colored staining in ex vivo validation part of animal experiments.

MATERIALS AND METHODS

The custom-formulated contrast dye namely red iodized oil (RIO) was prepared by solubilizing a lipophilic dye Oil Red O in iodized poppy seed oil (Lipiodol or LPD) followed by physicochemical characterizations. To explore and test the utility of RIO, normal rats (n = 10) and rabbits (n = 10) with myocardial infarction (MI) were euthanized by overdose of pentobarbital for infusion of RIO through catheterization. The bodies and/or excised organs including heart, liver, spleen, kidneys, pancreas, and intestines of the rats and rabbits were imaged at clinical mammography, CT and MRI units. These images were qualitatively studied and quantitatively analyzed using Wilcoxon Rank test with a P value < 0.05 being considered of a statistically significant difference. Imaging findings were verified by histomorphology.

RESULTS

All experimental procedures were carried out successfully with the use of RIO. T1 and T2 relaxation time was 234.2 ± 2.6 ms and 141.9 ± 3.0 ms for RIO, close to that of native LPD. Proton ((1) H) NMR spectroscopy revealed almost identical profiles between RIO and native LPD. The clinical mammography unit, 128-slice CT scanner and 3.0T MRI magnet were well adapted for the animal experiments. Combined use of RIO with DR, MRI, CT and histology enabled microangiography of the organs, 3D visualization of rat pancreas, validation of in vivo cardiac quantification of MI and cause determination of the rabbit death after coronary occlusion. RIO appeared as red droplets and vacuoles in vessels by frozen and paraffin sections. Image analysis showed the superiority of DR images, which provided better overall image quality (4.35 ± 0.49) for all analyzed liver vessel segments. MRI images revealed moderate to good overall image quality ratings (3.45 ± 0.52). Comparing the signal intensities of vessel and liver with different MRI sequences, all P values were <0.01.

CONCLUSIONS

RIO proved to be a multifunctional contrast dye, which could be applied as an imaging biomarker for tissue vascularity or blood perfusion, for visualization of organ anatomy and for ex vivo validation of in vivo animal experiments.

The Tumor Microenvironment as a Barrier to Cancer Nanotherapy

Although extensive research effort and resources have been dedicated to the development of nanotherapeutics to treat cancer, few formulations have reached clinical application. A major reason is that the large number of parameters available to tune nanotherapy characteristics coupled with the variability in tumor tissue precludes evaluation of complex interactions through experimentation alone. In order to optimize the nanotechnology design and gain further insight into these phenomena, mathematical modeling and computational simulation have been applied to complement empirical work. In this chapter, we discuss modeling work related to nanotherapy and the tumor microenvironment. We first summarize the biology underlying the dysregulated tumor microenvironment, followed by a description of major nano-scale parameters. We then present an overview of the mathematical modeling of cancer nanotherapy, including evaluation of nanotherapy in multi-dimensional tumor tissue, coupling of nanotherapy with vascular flow, modeling of nanotherapy in combination with in vivo imaging, modeling of nanoparticle transport based on in vitro data, modeling of vasculature-bound nanoparticles, evaluation of nanotherapy using pharmacokinetic modeling, and modeling of nano-based hyperthermia. We conclude that an even tighter interdisciplinary effort between biological, material, and physical scientists is needed in order to eventually overcome the tumor microenvironment barrier to successful nanotherapy.

Computed tomography of Lipiodol-loaded biodegradable pasty polymer for implant visualization

Targeted delivery of drug-loaded implants for regional drug therapy has become an important approach to therapy. Simple and reproducible imaging methodologies to evaluate the implant noninvasively are needed. The goal of this work was to noninvasively evaluate the visibility, shape and degradation of a biodegradable implant containing Lipiodol (an X-ray contrast medium) by computed tomography (CT). For in vitro evaluation, Lipiodol was incorporated in poly(sebacic-co-ricinoleic acid) [P(SA:RA)], a biodegradable injectable pasty polymer, and CT visibility was assessed. For ex vivo evaluation, bovine liver was injected with the polymer-loaded Lipiodol; for in vivo evaluation rats were injected subcutaneously with Lipiodol in polymer and CT was performed. We show that polymer diameter at CT correlates with implant weight and pathological measurements. Polymer formulation containing 5% Lipiodol was visible on CT in vitro. Ex vivo tests showed a round polymer deposit at the injection site compared with free dispersion of Lipiodol alone. Correlation between implant size at CT scan and surgery at 48 h was R(2)  = 0.78. Average CT diameter at 9 days was 14.2 ± 2.8 mm in rats injected with Lipiodol in the polymer formulation, as compared with 7.3 ± 1.1 mm in controls. After 9 days, the implant degraded into several zones containing inflammatory cells seen on CT as areas with increased heterogeneity. In conclusion, Lipiodol incorporated in P(SA:RA) is visible on CT, and polymer degradation can potentially be monitored noninvasively. This method can be widely applied to follow changes in biodegradable implants.

Treatment of Liver Tumors with Lipiodol TACE: Technical Recommendations from Experts Opinion

Transarterial chemoembolization with Lipiodol (Lipiodol TACE), also called conventional TACE, was developed in the early 1980s and widely adopted worldwide after randomized control trials and meta-analysis demonstrated superiority of Lipiodol TACE to best supportive care. Presently, there is no level one evidence that other TACE techniques are superior to Lipiodol TACE for intermediate stage hepatocellular carcinoma (HCC), which includes patients with preserved liver function and nonsurgical large or multinodular HCC without distant metastases. In addition, TACE is part of the treatment for progressive or symptomatic liver metastases from gastroenteropancreatic neuroendocrine tumors. When injected into the hepatic artery, Lipiodol has the unique property of selective uptake and retention in hyperarterialyzed liver tumors. Lipiodol/drug emulsion followed by particle embolization has been demonstrated to improve the pharmacokinetic of the drug and tumor response. Radio opacity of Lipiodol helps to monitor treatment delivery, with retention of Lipiodol serving as an imaging biomarker for tumor response. For 30 years, Lipiodol TACE has been inconsistently referenced in many publications with various levels of details for the method of preparation and administration, with reported progressive outcomes following improvements in the technique and the devices used to deliver the treatment and better patient selection. Consequently, there is no consensus on the standard method of TACE regarding the use of anticancer agents, embolic material, technical details, and the treatment schedule. In order to develop an internationally validated technical recommendation to standardize the Lipiodol TACE procedure, a worldwide panel of experts participated in a consensus meeting held on May 10, 2014 .

Cancer targeted therapeutics: From molecules to drug delivery vehicles

The pitfall of all chemotherapeutics lies in drug resistance and the severe side effects experienced by patients. One way to reduce the off-target effects of chemotherapy on healthy tissues is to alter the biodistribution of drug. This can be achieved in two ways: Passive targeting utilizes shape, size, and surface chemistry to increase particle circulation and tumor accumulation. Active targeting employs either chemical moieties (e.g. peptides, sugars, aptamers, antibodies) to selectively bind to cell membranes or responsive elements (e.g. ultrasound, magnetism, light) to deliver its cargo within a local region. This article will focus on the systemic administration of anti-cancer agents and their ability to home to tumors and, if relevant, distant metastatic sites.

MRI-detectable polymeric micelles incorporating platinum anticancer drugs enhance survival in an advanced hepatocellular carcinoma model

Hepatocellular carcinoma (HCC) is one of the most intractable and lethal cancers; most cases are diagnosed at advanced stages with underlying liver dysfunction and are frequently resistant to conventional chemotherapy and radiotherapy. The development of tumor-targeting systems may improve treatment outcomes. Nanomedicine platforms are of particular interest for enhancing chemotherapeutic efficiency, and they include polymeric micelles, which enable targeting of multiple drugs to solid tumors, including imaging and therapeutic agents. This allows concurrent diagnosis, targeting strategy validation, and efficacy assessment. We used polymeric micelles containing the T1-weighted magnetic resonance imaging contrast agent gadolinium-diethylenetriaminpentaacetic acid (Gd-DTPA) and the parent complex of the anticancer drug oxaliplatin [(1,2-diaminocyclohexane)platinum(II) (DACHPt)] for simultaneous imaging and therapy in an orthotopic rat model of HCC. The Gd-DTPA/DACHPt-loaded micelles were injected into the hepatic artery, and magnetic resonance imaging performance and antitumor activity against HCC, as well as adverse drug reactions were assessed. After a single administration, the micelles achieved strong and specific tumor contrast enhancement, induced high levels of tumor apoptosis, and significantly suppressed tumor size and growth. Moreover, the micelles did not induce severe adverse reactions and significantly improved survival outcomes in comparison to oxaliplatin or saline controls. Our results suggest that Gd-DTPA/DACHPt-loaded micelles are a promising approach for effective diagnosis and treatment of advanced HCC.

Transarterial chemoembolization (TACE) for colorectal liver metastases--current status and critical review

BACKGROUND

Transarterial liver-directed therapies are currently not recommended as a standard treatment for colorectal liver metastases. Transarterial chemoembolization (TACE), however, is increasingly used for patients with liver-dominant colorectal metastases after failure of surgery or systemic chemotherapy. The limited available data potentially reveals TACE as a valuable option for pre- and post-operative downsizing, minimizing time-to-surgery, and prolongation of overall survival after surgery in patients with colorectal liver only metastases.

PURPOSE

In this overview, the current status of TACE for the treatment of liver-dominant colorectal liver metastases is presented. Critical comments on its rationale, technical success, complications, toxicity, and side effects as well as oncologic outcomes are discussed. The role of TACE as a valuable adjunct to surgery is addressed regarding pre- and post-operative downsizing, conversion to resectability as well as improvement of the recurrence rate after potentially curative liver resection. Additionally, the concept of TACE for liver-dominant metastatic disease with a focus on new embolization technologies is outlined.

CONCLUSIONS

There is encouraging data with regard to technical success, safety, and oncologic efficacy of TACE for colorectal liver metastases. The majority of studies are non-randomized single-center series mostly after failure of systemic therapies in the 2nd line and beyond. Emerging techniques including embolization with calibrated microspheres, with or without additional cytotoxic drugs, degradable starch microspheres, and technical innovations, e.g., cone-beam computed tomography (CT) allow a new highly standardized TACE procedure. The real efficacy of TACE for colorectal liver metastases in a neoadjuvant, adjuvant, and palliative setting has now to be evaluated in prospective randomized controlled trials.