Characterization of drug release from fibrin gels loaded with different pharmaceutical and experimental doxorubicin formulations

An Up-to-date Review on Protein-based Nanocarriers in the Management of Cancer

BACKGROUND

A big health issue facing the world's population is cancer. An alarming increase in cancer patients was anticipated by worldwide demographic statistics, which showed that the number of patients with different malignancies was rapidly increasing. By 2025, probably 420 million cases were projected to be achieved. The most common cancers diagnosed are breast, colorectal, prostate, and lung. Conventional treatments, such as surgery, chemotherapy, and radiation therapy, have been practiced.

OBJECTIVE

In recent years, the area of cancer therapy has changed dramatically with expanded studies on the molecular-level detection and treatment of cancer. Recent advances in cancer research have seen significant advances in therapies such as chemotherapy and immunotherapy, although both have limitations in effectiveness and toxicity.

METHODS

The development of nanotechnology for anticancer drug delivery has developed several potentials as nanocarriers, which may boost the pharmacokinetic and pharmacodynamic effects of the drug product and substantially reduce the side effects.

RESULTS

The advancement in non-viral to viral-based protein-based nanocarriers for treating cancer has earned further recognition in this respect. Many scientific breakthroughs have relied on protein-based nanocarriers, and proteins are essential organic macromolecules for life. It allows targeted delivery of passive or active tumors using non-viral-based protein-based nanocarriers to viral-based protein nanocarriers. When targeting cancer cells, both animal and plant proteins may be used in a formulation process to create self-assembled viruses and platforms that can successfully eradicate metastatic cancer cells.

CONCLUSION

This review, therefore, explores in depth the applications of non-viral to viral proteinbased noncarriers with a specific focus on intracellular drug delivery and anti-cancer drug targeting ability.

Mesenchymal stem cell secretome-loaded fibrin glue improves the healing of intestinal anastomosis

Anastomotic leakage is a serious complication following gastrointestinal surgery and one of the leading causes of patient mortality. Despite the significant clinical and economic burden, there are currently no reliable treatment options to improve the healing of intestinal anastomosis and subsequently prevent anastomotic leakage. Recently, the development of regenerative medicine has shown promise for improving anastomotic healing. Recent studies have illustrated that stem cell-derived secretome can enhance tissue regeneration without the safety and ethical limitations of stem cell transplantation. Herein, we developed a fibrin glue topical delivery system loaded with mesenchymal stem cells (MSCs)-derived secretome for controlled delivery of bioactive factors, and evaluated its application potential in improving the healing of intestinal anastomosis. Under in vitro conditions, the MSCs secretome significantly promoted cell proliferation viability in a dose-dependent manner and resulted in the controlled release of growth factors via fibrin glue delivery. We established a rat surgical anastomotic model and experimentally found that MSCs secretome-loaded fibrin glue enhanced anastomotic bursting pressure, increased granulation tissue formation and collagen deposition, and significantly promoted anastomotic healing. Mechanistically, fibrin glue accelerated cell proliferation, angiogenesis, and macrophage M2 polarization at the surgical anastomotic site by releasing bioactive factors in the secretome, and it also alleviated the inflammatory response and cell apoptosis at the anastomotic site. Our results demonstrated for the first time that MSCs-derived secretome could promote the healing of intestinal anastomosis. Considering the accessibility and safety of the cell-free secretome, we believed that secretome-loaded fibrin glue would be a cell-free therapy to accelerate the healing of intestinal anastomosis with great potential for clinical translation.

Advances in Fibrin-Based Materials in Wound Repair: A Review

The first bioprocess that occurs in response to wounding is the deterrence of local hemorrhage. This is accomplished by platelet aggregation and initiation of the hemostasis cascade. The resulting blood clot immediately enables the cessation of bleeding and then functions as a provisional matrix for wound healing, which begins a few days after injury. Here, fibrinogen and fibrin fibers are the key players, because they literally serve as scaffolds for tissue regeneration and promote the migration of cells, as well as the ingrowth of tissues. Fibrin is also an important modulator of healing and a host defense system against microbes that effectively maintains incoming leukocytes and acts as reservoir for growth factors. This review presents recent advances in the understanding and applications of fibrin and fibrin-fiber-incorporated biomedical materials applied to wound healing and subsequent tissue repair. It also discusses how fibrin-based materials function through several wound healing stages including physical barrier formation, the entrapment of bacteria, drug and cell delivery, and eventual degradation. Pure fibrin is not mechanically strong and stable enough to act as a singular wound repair material. To alleviate this problem, this paper will demonstrate recent advances in the modification of fibrin with next-generation materials exhibiting enhanced stability and medical efficacy, along with a detailed look at the mechanical properties of fibrin and fibrin-laden materials. Specifically, fibrin-based nanocomposites and their role in wound repair, sustained drug release, cell delivery to wound sites, skin reconstruction, and biomedical applications of drug-loaded fibrin-based materials will be demonstrated and discussed.

Cyclodextrin Polymers as Delivery Systems for Targeted Anti-Cancer Chemotherapy

In the few last years, nanosystems have emerged as a potential therapeutic approach to improve the efficacy and selectivity of many drugs. Cyclodextrins (CyDs) and their nanoparticles have been widely investigated as drug delivery systems. The covalent functionalization of CyD polymer nanoparticles with targeting molecules can improve the therapeutic potential of this family of nanosystems. In this study, we investigated cross-linked γ- and β-cyclodextrin polymers as carriers for doxorubicin (ox) and oxaliplatin (Oxa). We also functionalized γ-CyD polymer bearing COOH functionalities with arginine-glycine-aspartic or arginine moieties for targeting the integrin receptors of cancer cells. We tested the Dox and Oxa anti-proliferative activity in the presence of the precursor polymer with COOH functionalities and its derivatives in A549 (lung, carcinoma) and HepG2 (liver, carcinoma) cell lines. We found that CyD polymers can significantly improve the antiproliferative activity of Dox in HepG2 cell lines only, whereas the cytotoxic activity of Oxa resulted as enhanced in both cell lines. The peptide or amino acid functionalized CyD polymers, loaded with Dox, did not show any additional effect compared to the precursor polymer. Finally, studies of Dox uptake showed that the higher antiproliferative activity of complexes correlates with the higher accumulation of Dox inside the cells. The results show that CyD polymers could be used as carriers for repositioning classical anticancer drugs such as Dox or Oxa to increase their antitumor activity.

Enhanced therapeutic index of liposomal doxorubicin Myocet locally delivered by fibrin gels in immunodeficient mice bearing human neuroblastoma

Caelyx and Myocet are clinically used liposomal forms of doxorubicin (Dox). To explore ways to improve their therapeutic index, we have studied their activity in vitro and in vivo when locally delivered by fibrin gels (FBGs). In vivo local toxic and anti-tumour activities of loaded FBGs were assessed in two immunodeficient mouse orthotopic human neuroblastoma (NB) models after application in the visceral space above the adrenal gland, either still tumour-bearing or after tumour removal. In parallel, in vitro assays were used to mimic the in vivo overlaying of FBGs on the tumour surface. FBGs were prepared with different concentrations of fibrinogen (FG) and clotted in the presence of Ca2+ and thrombin. The in vitro assays showed that FBGs loaded with Myocet possess a cytotoxic activity against NB cell lines generally greater than those loaded with free Dox or Caelyx. In vivo FBGs loaded with Myocet showed lower general and local toxicities as compared to gels loaded with Caelyx or free Dox, and also to free Dox administered i.v. (all treatments with Dox at 2.5 mg/Kg). The anti-tumour activity, evaluated in the two mouse orthotopic NB models of adjuvant and neo-adjuvant therapy, resulted in a better performance of FBGs loaded with Myocet compared to the other local (FBGs loaded with Caelyx or free Dox) or systemic (free Dox) treatments (administered at 2.5 and 5 mg/Kg Dox). Specifically, the application of FBGs at 40 mg/mL in the adjuvant model caused 92 % tumour volume reduction, while by the neo-adjuvant application of FBGs at 22 mg/mL a re-growing tumour volume reduction of 89 % was obtained. Taken together, our in vitro and in vivo results indicate a significantly higher activity for the FBGs loaded with Myocet. In particular, the lower toicity coupled with the higher anti-tumour activity on both the local treatment modalities strongly suggest a better therapeutic index when Myocet is administered through FBGs. Therefore, FBGs loaded with Myocet may be considered as a possible new tool for the loco-regional treatment of NB or even other tumour histotypes treatable by loco-regional chemotherapy.

Serum protein-based nanoparticles for cancer diagnosis and treatment

Serum protein as naturally essential biomacromolecules has recently emerged as a versatile carrier for diagnostic and therapeutic drug delivery for cancer nanomedicine with superior biocompatibility, improved pharmacokinetics and enhanced targeting capacity. A variety of serum proteins have been utilized for drug delivery, mainly including albumin, ferritin/apoferritin, transferrin, low-density lipoprotein, high-density lipoprotein and hemoglobin. As evidenced by the success of paclitaxel-bound albumin nanoparticles (Abraxane^TM), serum protein-based nanoparticles have gained attractive attentions for precise biological design and potential clinical application. In this review, we summarize the general design strategies, targeting mechanisms and recent development of serum protein-based nanoparticles in the field of cancer nanomedicine. Moreover, we also concisely specify the current challenges to be addressed for a bright future of serum protein-based nanomedicines.

Fibrin Matrices as (Injectable) Biomaterials: Formation, Clinical Use, and Molecular Engineering

This review focuses on fibrin, starting from biological mechanisms (its production from fibrinogen and its enzymatic degradation), through its use as a medical device and as a biomaterial, and finally discussing the techniques used to add biological functions and/or improve its mechanical performance through its molecular engineering. Fibrin is a material of biological (human, and even patient's own) origin, injectable, adhesive, and remodellable by cells; further, it is nature's most common choice for an in situ forming, provisional matrix. Its widespread use in the clinic and in research is therefore completely unsurprising. There are, however, areas where its biomedical performance can be improved, namely achieving a better control over mechanical properties (and possibly higher modulus), slowing down degradation or incorporating cell-instructive functions (e.g., controlled delivery of growth factors). The authors here specifically review the efforts made in the last 20 years to achieve these aims via biomimetic reactions or self-assembly, as much via formation of hybrid materials.

Fibrin gels entrapment of a doxorubicin-containing targeted polycyclodextrin: Evaluation of in vivo antitumor activity in orthotopic models of human neuroblastoma

In vivo local antitumor activity of fibrin gels (FBGs) loaded with the poly-cyclodextrin oCD-NH₂/Dox, compared to free Dox, was evaluated in two mouse orthotopic neuroblastoma (NB) models, after positioning of the releasing devices in the visceral space. FBGs were prepared at the fibrinogen (FG) concentrations of 22 and 40 mg/ml clotted in the presence of 0.81 mM/mg FG Ca²⁺ and 1.32 U/mg FG thrombin. Our results indicate that FBGs loaded with oCD-NH₂/Dox and applied as neoadjuvant loco-regional treatment, show an antitumor activity significantly greater than that displayed by the same FBGs loaded with identical dose of Dox or after free Dox administered intra venous (iv). In particular, FBGs prepared at 40 mg/ml showed a slightly lower antitumor activity, although after their positioning we observed a significant initial reduction of tumor burden lasting for several days after gel implantation. FBGs at 22 mg/ml loaded with oCD-NH₂/Dox and applied after tumor removal (adjuvant treatment model) showed a significantly better antitumor activity than the iv administration of free Dox, with 90% tumor regrowth reduction compared to untreated controls. In all cases the weight loss post-treatment was limited after gel application, although in the adjuvant treatment the loss of body weight lasted longer than in the other treatment modality. In accordance with our recent published data on the low local toxic effects of FBGs, the present findings also underline an increase of the therapeutic index of Dox when locally administered through FBGs loaded with the oCD-NH₂/Dox complex.

Fibrin Gels Entrapment of a Poly-Cyclodextrin Nanocarrier as a Doxorubicin Delivery System in an Orthotopic Model of Neuroblastoma: Evaluation of In Vitro Activity and In Vivo Toxicity

PURPOSE

Fibrin gels (FBGs) are potential delivery vehicles for many drugs, and can be easily prepared from purified components. We previously demonstrated their applicability for the release of different doxorubicin (Dox) nanoparticles used clinically or in an experimental stage, such as its inclusion complex with the amino β-cyclodextrin polymer (oCD-NH₂/Dox). Here we extend these studies by in vitro and in vivo evaluations.

METHODS

An in vitro cytotoxicity model consisting of an overlay of a neuroblastoma (NB) cell-containing agar layer above a drug-loaded FBG layer was used. Local toxicity in vivo (histology and blood analysis) was studied in a mouse orthotopic NB model (SHSY5YLuc⁺ cells implanted into the left adrenal gland).

RESULTS

In vitro data show that FBGs loaded with oCD-NH₂/Dox have a slightly lower cytotoxicity against NB cell lines than those loaded with Dox. Fibrinogen (FG), and Ca²⁺ concentrations may modify this activity. In vivo data support a lower general and local toxicity for FBGs loaded with oCD-NH₂/Dox than those loaded with Dox.

CONCLUSION

Our results suggest a possible increase of the therapeutic index of Dox when locally administered through FBGs loaded with oCD-NH₂/Dox, opening the possibility of using these releasing systems for the treatment of neuroblastoma.