Antitumor effect of an injectable in-situ forming drug delivery system composed of a novel tissue adhesive containing doxorubicin hydrochloride

Locoregional drug delivery for cancer therapy: Preclinical progress and clinical translation

Systemic drug delivery is the current clinically preferred route for cancer therapy. However, challenges associated with tumor localization and off-tumor toxic effects limit the clinical effectiveness of this route. Locoregional drug delivery is an emerging viable alternative to systemic therapies. With the improvement in real-time imaging technologies and tools for direct access to tumor lesions, the clinical applicability of locoregional drug delivery is becoming more prominent. Theoretically, locoregional treatments can bypass challenges faced by systemic drug delivery. Preclinically, locoregional delivery of drugs has demonstrated enhanced therapeutic efficacy with limited off-target effects while still yielding an abscopal effect. Clinically, an array of locoregional strategies is under investigation for the delivery of drugs ranging in target and size. Locoregional tumor treatment strategies can be classified into two main categories: 1) direct drug infusion via injection or implanted port and 2) extended drug elution via injected or implanted depot. The number of studies investigating locoregional drug delivery strategies for cancer treatment is rising exponentially, in both preclinical and clinical settings, with some approaches approved for clinical use. Here, we highlight key preclinical advances and the clinical relevance of such locoregional delivery strategies in the treatment of cancer. Furthermore, we critically analyze 949 clinical trials involving locoregional drug delivery and discuss emerging trends.

Injectable, Adhesive Albumin Nanoparticle-Incorporated Hydrogel for Sustained Localized Drug Delivery and Efficient Tumor Treatment

Injectable hydrogels are receiving increasing attention as local depots for sustained anticancer drug delivery. However, most current hydrogel-based carriers lack tissue-adhesive ability, a property that is important for the immobilization of drug-loaded systems at tumor sites to increase local drug concentration. In this study, we developed a paclitaxel (PTX)-loaded injectable hydrogel with firm tissue adhesion for localized tumor therapy. PTX-loaded bovine serum albumin (BSA) nanoparticles (PTX@BN) were prepared, and the drug-loaded hydrogel was then fabricated by cross-linking PTX@BN with o-phthalaldehyde (OPA)-terminated 4-armed poly(ethylene glycol) (4aPEG-OPA) via a condensation reaction between OPA and the amines in BSA. The hydrogel showed firm adhesion to various organs and tumor tissues ex vivo due to the condensation reaction of unreacted OPA groups and amines in the tissues. The PTX-loaded nanocomposite hydrogels sustained PTX release over 30 days following the Korsmeyer-Peppas model and exhibited notable inhibition activities against mouse C26 colon and 4T1 breast cancer cells in vitro. Following peritumoral injection into mice with C26 or 4T1 tumors, the PTX@BN-loaded hydrogel significantly enhanced the antitumor efficacy and prolonged animal survival time compared to free PTX solutions with low systemic toxicity. Therefore, the adhesive, PTX-loaded nanocomposite hydrogels have the potential for efficient localized tumor therapy.

Bioadhesive Technology Platforms

Bioadhesives have emerged as transformative and versatile tools in healthcare, offering the ability to attach tissues with ease and minimal damage. These materials present numerous opportunities for tissue repair and biomedical device integration, creating a broad landscape of applications that have captivated clinical and scientific interest alike. However, fully unlocking their potential requires multifaceted design strategies involving optimal adhesion, suitable biological interactions, and efficient signal communication. In this Review, we delve into these pivotal aspects of bioadhesive design, highlight the latest advances in their biomedical applications, and identify potential opportunities that lie ahead for bioadhesives as multifunctional technology platforms.

EGFR Targeted Cetuximab-Valine-Citrulline (vc)-Doxorubicin Immunoconjugates- Loaded Bovine Serum Albumin (BSA) Nanoparticles for Colorectal Tumor Therapy

Background

Specific modifications to carriers to achieve targeted delivery of chemotherapeutics into malignant tissues are a critical point for efficient diagnosis and therapy. In this case, bovine serum albumin (BSA) was conjugated with cetuximab–valine–citrulline (vc)–doxorubicin (DOX) to target epidermal growth factor receptor (EGFR) and enable the release of drug in EGFR-overexpressed tumor cells.

Methods

Maleimidocaproyl–valine–citrulline–p-aminobenzylcarbonyl-p-nitrophenol (MC-Val-Cit-PAB-PNP) and DOX were used to synthesize MC-Val-Cit-PAB-DOX, which was further linked with cetuximab to prepare antibody–drug conjugates (ADCs). Then, the ADCs were adsorbed to the surface of the BSA nanoparticles (NPs), which were prepared by a desolvation method to obtain cetuximab-vc-DOX-BSA-NPs. The cetuximab-vc-DOX conjugates adsorbed on the surface of the BSA nanoparticles were determined and optimized by size exclusion chromatography. An in vitro cytotoxicity study was conducted using a colon carcinoma cell line with different EGFR-expression levels to test the selectivity of cetuximab-vc-DOX-NPs.

Results

The vc-DOX and cetuximab-vc-DOX conjugates were both synthesized successfully and their structural characteristics confirmed by ¹H-NMR and SDS-PAGE. The MTT assay showed stronger cytotoxicity of cetuximab-vc-DOX-NPs versus control IgG-vc-DOX-NPs in EGFR–overexpressing RKO cells. Cellular binding and intracellular accumulation determined by flow cytometry and confocal laser scanning microscopy revealed the strong binding ability of cetuximab-vc-DOX-NPs to RKO cells. The in vivo imaging study demonstrated that cetuximab-vc-DOX-NPs exhibited higher fluorescent intensity in tumor tissues than non-decorated nanoparticles (IgG-vc-DOX-NPs). In vivo tumor inhibition and survival tests showed that cetuximab-vc-DOX-NPs revealed higher tumor inhibition efficacy and lower systemic toxicity than control IgG-vc-DOX- NPs

Conclusion

The obtained results emphasize that cetuximab-vc-DOX-NPs, with good tumor-targeting ability and low systemic toxicity, are a promising targeting system for drug delivery.

Polymeric Tissue Adhesives

Polymeric tissue adhesives provide versatile materials for wound management and are widely used in a variety of medical settings ranging from minor to life-threatening tissue injuries. Compared to the traditional methods of wound closure (i.e., suturing and stapling), they are relatively easy to use, enable rapid application, and introduce minimal tissue damage. Furthermore, they can act as hemostats to control bleeding and provide a tissue-healing environment at the wound site. Despite their numerous current applications, tissue adhesives still face several limitations and unresolved challenges (e.g., weak adhesion strength and poor mechanical properties) that limit their use, leaving ample room for future improvements. Successful development of next-generation adhesives will likely require a holistic understanding of the chemical and physical properties of the tissue-adhesive interface, fundamental mechanisms of tissue adhesion, and requirements for specific clinical applications. In this review, we discuss a set of rational guidelines for design of adhesives, recent progress in the field along with examples of commercially available adhesives and those under development, tissue-specific considerations, and finally potential functions for future adhesives. Advances in tissue adhesives will open new avenues for wound care and potentially provide potent therapeutics for various medical applications.

In situ gelation properties of a collagen-genipin sol with a potential for the treatment of gastrointestinal ulcers

We investigated the potential of collagen-genipin sols as biomaterials for treating artificial ulcers following endoscopic submucosal dissection. Collagen sol viscosity increased with condensation, allowing retention on tilted ulcers before gelation and resulting in collagen gel deposition on whole ulcers. The 1.44% collagen sols containing genipin as a crosslinker retained sol fluidity at 23°C for >20 min, facilitating endoscopic use. Collagen sols formed gel depositions on artificial ulcers in response to body temperature, and high temperature responsiveness of gelation because of increased neutral phosphate buffer concentration allowed for thick gel deposition on tilted ulcers. Finally, histological observations showed infiltration of gels into submucosal layers. Taken together, the present data show that genipin-induced crosslinking significantly improves the mechanical properties of collagen gels even at low genipin concentrations of 0.2-1 mM, warranting the use of in situ gelling collagen-genipin sols for endoscopic treatments of gastrointestinal ulcers.

Engineered in-situ depot-forming hydrogels for intratumoral drug delivery

Chemotherapy is the traditional treatment for intermediate and late stage cancers. The search for treatment options with minimal side effects has been ongoing for several years. Drug delivery technologies that result in minimal or no side effects with improved ease of use for the patients are receiving increased attention. Polymer drug conjugates and nanoparticles can potentially offset the volume of drug distribution while enhancing the accumulation of the active drug in tumors thereby reducing side effects. Additionally, development of localized drug delivery platforms is being investigated as another key approach to target tumors with minimal or no toxicity. Development of in-situ depot-forming gel systems for intratumoral delivery of immuno-oncology actives can enhance drug bioavailability to the tumor site and reduce systemic toxicity. This field of drug delivery is critical to develop given the advent of immunotherapy and the availability of novel biological molecules for treating solid tumors. This article reviews the advances in the field of engineered in-situ gelling platforms as a practical tool for local delivery of active oncolytic agents to tumor sites.

A Facile Strategy for In Situ Controlled Delivery of Doxorubicin with a pH-Sensitive Injectable Hydrogel

In light of the challenges along with the traditional intravenous administration of chemotherapeutics, injectable hydrogel-drug system emerges as a powerful tool for noninvasive and in situ controlled-release of drugs. Herein, we report a novel strategy of drug delivery system with pH responsive injectable hydrogels by taking advantages of two biomaterials. The first one is a pH sensitive polymer-drug (prodrug) conjugate, poly (ethylene glycol)–doxorubicin (MPEG–DOX) with hydrazone linkage. This prodrug interacted with a second biomaterial, α-cyclodextrin (α-CD) under mild conditions and subsequently formed the hydrogels in minutes with tunable stiffness. The gels showed a sustained release behavior dependent on the surrounding pH and released drugs effectively killed tumor cells (MCF-7). The quick cell uptake and efficient intracellular delivery of DOX were observed under a confocal microscope. This study thus provides a novel and simple drug encapsulation strategy to deliver poorly soluble drugs in situ for a potential targeted chemotherapy.

Electrostatic unfolding and interactions of albumin driven by pH changes: a molecular dynamics study

A better understanding of protein aggregation is bound to translate into critical advances in several areas, including the treatment of misfolded protein disorders and the development of self-assembling biomaterials for novel commercial applications. Because of its ubiquity and clinical potential, albumin is one of the best-characterized models in protein aggregation research; but its properties in different conditions are not completely understood. Here, we carried out all-atom molecular dynamics simulations of albumin to understand how electrostatics can affect the conformation of a single albumin molecule just prior to self-assembly. We then analyzed the tertiary structure and solvent accessible surface area of albumin after electrostatically triggered partial denaturation. The data obtained from these single protein simulations allowed us to investigate the effect of electrostatic interactions between two proteins. The results of these simulations suggested that hydrophobic attractions and counterion binding may be strong enough to effectively overcome the electrostatic repulsions between the highly charged monomers. This work contributes to our general understanding of protein aggregation mechanisms, the importance of explicit consideration of free ions in protein solutions, provides critical new insights about the equilibrium conformation of albumin in its partially denatured state at low pH, and may spur significant progress in our efforts to develop biocompatible protein hydrogels driven by electrostatic partial denaturation.

A novel hemostatic sealant composed of gelatin, transglutaminase and thrombin effectively controls liver trauma-induced bleeding in dogs

AIM

novel hemostatic sealant based on the in situ gel formation of gelatin catalyzed by thrombin and crosslinked by transglutaminase was designed. The aim of this study was to investigate the efficacy of the hemostatic sealant in control of bleeding caused by liver trauma in dogs.

METHODS

Hepatic trauma that mimicked the grade III-IV rupture of liver was made in 20 dogs. The traumatic lesion was topically administered the hemostatic sealant (treatment group, n=10), or a thrombin solution (control group, n=10). The time to achieve hemostasis and the blood loss were measured. Contrast-enhanced ultrasound (CEUS) examination was performed in each animal on d 3, d 7, and d 10 d postoperatively to study the healing of the lesions.

RESULTS

The mean time to achieve hemostasis in the treatment group was significantly shorter than that in the control group (1.20±0.33 vs 6.70±0.64 min, P<0.05). The mean blood loss in the treatment group was significantly less than that in the control group (47.22±8.61 vs 79.29±11.97 mL, P<0.05). In CEUS examination, the traumatic lesions in the treatment group became significantly smaller on d 3, and disappeared on d 7, whereas the lesions in the control group still existed on d 10. Ascites were never found during 10 d follow-up in the treatment group but were observed on d 3 and d 7 in the control group.

CONCLUSION

Compared with thrombin, the novel hemostatic sealant shows much better efficacy in hemostasis and may promote wound healing in dog liver trauma.

Injectable in situ forming controlled release implant composed of a poly-ether-ester-carbonate and applications in the field of chemotherapy

Polymeric controlled delivery systems hold great promise in the field of modern medicine. Such technology has already been converted into commercially viable products in a myriad of fields. Chemotherapy is an example of such an area where constant efficacious levels of drug can greatly enhance clinical outcomes. The key to designing such therapies is the preparation of the proper delivery system. To this end, a series of bioresorbable polyether-ester-carbonate copolymers have been developed, which when combined with a diluent, are capable injection into the body and consistently forming a drug delivery depot. The study delineated here aimed at producing a more effective treatment of a common drug, paclitaxel, using the polymeric carrier. The polymer carrier system exhibited controlled release of paclitaxel both in vitro and in vivo. Drug concentrations were analyzed by high performance liquid chromatography and apoptotic activity was confirmed through flow cytometry. Relevant success was exhibited by the regression of tumor size following a multiple injection treatment regimen in a murine xenograft model. This multiple injection treatment shows promising results when compared to the traditional paclitaxel paradigm of a single injection for a period of 3 weeks.

Local drug delivery strategies for cancer treatment: gels, nanoparticles, polymeric films, rods, and wafers

Polymer-based drug delivery depots have been investigated over the last several decades as a means to improve upon the lack of tumor targeting and severe systemic morbidities associated with intravenous chemotherapy treatments. These localized therapies exist in a variety of form factors designed to facilitate the delivery of drug directly to the site of disease in a controlled manner, sparing off-target tissue toxicities. Many of these depots are biodegradable and designed to maintain therapeutic concentrations of drug at the tumor site for a prolonged period of time. Thus a single implantation procedure is required, sometimes coincident with tumor excision surgery, and thereby biodegrading following complete release of the loaded active agent. Even though localized polymer depot delivery systems have been investigated, a surprisingly small subset of these technologies has demonstrated potentially curative preclinical results for cancer applications, and fewer have progressed toward commercialization. The aims of this article are to review the most well-studied and efficacious local polymer delivery systems from the last two decades, to examine the rationale for utilizing drug-eluting polymer implants in cancer patients, and to identify the patient cohorts that could most benefit from localized therapy. Finally, a discussion of the physiological barriers to localized therapy (i.e. drug penetration, transport), technical hurdles, and future outlook of the field is presented.

Application of hydroxyapatite nanoparticles in development of an enhanced formulation for delivering sustained release of triamcinolone acetonide

We report an analysis of in vitro and in vivo drug release from an in situ formulation consisting of triamcinolone acetonide (TR) and poly(d,l-lactide-co-glycolide) (PLGA) and the additives glycofurol (GL) and hydroxyapatite nanoparticles (HA). We found that these additives enhanced drug release rate. We used the Taguchi method to predict optimum formulation variables to minimize the initial burst. This method decreased the burst rate from 8% to 1.3%. PLGA-HA acted as a strong buffer, thereby preventing tissue inflammation at the injection site caused by the acidic degradation products of PLGA. Characterization of the optimized formulation by a variety of techniques, including scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and Fourier transform near infrared spectroscopy, revealed that the crystalline structure of TR was converted to an amorphous form. Therefore, this hydrophobic agent can serve as an additive to modify drug release rates. Data generated by in vitro and in vivo experiments were in good agreement.

Polymeric drug delivery systems for localized cancer chemotherapy

Cancer has become one of the most difficult health challenges of our time, accounting for millions of deaths yearly. Systemic chemotherapy is the most common therapeutic approach; however, considerable limitations exist including toxicities to healthy tissues and low achievable drug concentrations at tumor sites. More than 85% of human cancers are solid tumors, which can greatly benefit from localized delivery. This approach allows for high drug concentrations at the target site, lower systemic toxicity, and extended drug exposure which may be beneficial for cell cycle-specific drugs. Polymers have been widely considered in the development of localized delivery systems. This review focuses on both natural and synthetic biodegradable polymers that have been explored for localized chemotherapy, exploring their advantages, disadvantages, and clinical potential while citing examples of their use in pre-clinical development.

Injectable in situ forming drug delivery system based on poly(epsilon-caprolactone fumarate) for tamoxifen citrate delivery: Gelation characteristics, in vitro drug release and anti-cancer evaluation

The present study deals with the preparation and characterization of an injectable and in situ forming drug delivery system based on photocrosslinked poly(epsilon-caprolactone fumarate) (PCLF) networks loaded with tamoxifen citrate (TC). Networks were made of PCLF macromers, a photoinitiation system (comprising initiator and accelerator) and the active ingredient N-vinyl-2-pyrrolidone (NVP) as a crosslinker and reactive diluent. Shrinkage behavior, equilibrium swelling and sol fraction ratios of photocrosslinked PCLF gels were determined as functions of NVP content. It was shown that the crosslinking is facilitated up to a certain concentration of NVP and most of NVP remained unreacted above this value. In vitro drug release, biocompatibility evaluation and activity against MCF-7 breast cancer cell line were also investigated. Accurate but simple bipartite expressions were also derived that enable rapid determination of effective diffusion coefficients of TC in photocrosslinked PCLF/NVP disks. Cytotoxicity assay showed that while the photocrosslinked PCLF network with optimum NVP content exhibits no significant cytotoxicity against MCF-7 and L929 cell lines, 40-60% of the MCF-7 cells were killed after incubation with TC-loaded devices.

Recent advances in protection against doxorubicin-induced toxicity

Anthracycline antibiotics are among the most effective and commonly used anticancer drugs. Unfortunately, their clinical use is restricted by dose-dependent toxicity. Doxorubicin is an anthracycline antibiotic and cytotoxic (antineoplastic) agent. It is commonly used against ovarian, breast, lung, uterine and cervical cancers, Hodgkin's disease, soft tissue and primary bone sarcomas, as well against in several other cancer types. It has been shown that free radicals are involved in doxorubicin-induced toxicity. Doxorubicin causes the generation of free radicals and the induction of oxidative stress, associated with cellular injury. This review illustrates recent applications of different natural products, drugs, drug delivery systems, and approaches for protection against doxorubicin-induced toxicity (2006-present).