Current developments in drug delivery with thermosensitive liposomes.

Thermosensitive liposomes (TSLs) have been an important research area in the field of tumor targeted chemotherapy. Since the first TSLs appeared that using 1,2-dipalmitoyl-sn-glyce-ro-3-phosphocholine (DPPC) as the primary liposomal lipid, many studies have been done using this type of liposome from basic and practical aspects. While TSLs composed of DPPC enhance the cargo release near the phase transition temperature, it has been shown that many factors affect their temperature sensitivity. Thus numerous attempts have been undertaken to develop new TSLs for improving their thermal response performance. The main objective of this review is to introduce the development and recent update of innovative TSLs formulations, including combination of radiofrequency ablation (RFA), high-intensity focused ultrasound (HIFU), magnetic resonance imaging (MRI) and alternating magnetic field (AMF). In addition, various factors affecting the design of TSLs, such as lipid composition, surfactant, size and serum components are also discussed.

Inorganic kernel - Supported asymmetric hybrid vesicles for targeting delivery of STAT3-decoy oligonucleotides to overcome anti-HER2 therapeutic resistance of BT474R.

As a recombinant humanized monoclonal antibody that targets the extracellular region of HER2 tyrosine kinase receptor, trastuzumab (TRAZ) has demonstrated comparable clinical efficacy and improved survival in patients with HER2-positive breast cancer. Nevertheless, the therapeutic potential of TRAZ is often limited due to its frequent resistance to anti-HER2 therapy. Therefore, we investigate the reversal effect of STAT3-specific decoy oligonucleotides (STAT3-decoy ODNs) on TRAZ resistance, which contain the consensus sequence within the targeted gene promoter of STAT3. Considering the shortcomings of poor cellular permeability and rapid degradation in vivo limit the further clinical applications of ODNs, we report here an asymmetric hybrid lipid/polymer vesicles with calcium phosphate as the solid kernel (CaP@HA). Through hyaluronan-mediated CD44 targeting, the constructed vesicles can specifically carry STAT3-decoy ODNs into TRAZ-resistant breast cancer cells and then regulate TRAZ-induced apoptosis. In comparison with the native ones, ODNs packaged with CaP@HA showed significantly increased serum stability, cellular transfection, synergistic cytotoxicity and apoptosis in vitro. The improved TRAZ sensitization is attributed to the blockade of STAT3 signaling as well as the expression of downstream target genes associated with TRAZ resistance. With the synergistic action of STAT3-decoy ODNs loaded CaP@HA, TRAZ inhibited the growth of its resistant breast cancer xenograft dramatically and induced significant tumor cell apoptosis in vivo. These results suggested that CaP@HA mediated targeted delivery of STAT3-decoy ODNs might be a promising new strategy to overcome anti-HER2 resistance in breast cancer therapy.

Inorganic Kernel-Reconstituted Lipoprotein Biomimetic Nanovehicles Enable Efficient Targeting "Trojan Horse" Delivery of STAT3-Decoy Oligonucleotide for Overcoming TRAIL Resistance.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis in a variety of tumor cells, but not most normal cells. Nevertheless, its therapeutic potential is limited due to the frequent occurrence of resistance in tumor cells, especially hepatocellular carcinoma cell lines. Therefore, we investigated the reversal effect of STAT3-decoy oligonucleotides (ODNs) on TRAIL resistance. Methods. Considering that the drawback of poor cellular permeability and rapid degradation in vivo limited ODNs' further clinical applications, we developed a biomimetic calcium phosphate-reconstituted low density lipoprotein nanovehicle (CaP@LDL) that would serve as a "Trojan horse" to carry STAT3-decoy ODNs into tumor cells and then regulate TRAIL-induced apoptosis. Results. In comparison with native ODNs, the reconstituted CaP@LDL packaged ODNs showed significantly increased serum stability, cellular transfection, in vitro synergistic cytotoxicity and apoptosis in hepatoma cells, while there was no cytotoxicity to normal cells. The improved TRAIL sensitization is attributed to blocking of STAT3 signaling and consequent expression of the downstream target antiapoptotic gene. Following systemic administration, CaP@LDL displayed LDL-mimicking pharmacokinetic behavior such as attenuated blood clearance as well as enhanced accumulation in tumor and hepatorenal sites. With the synergistic combination of decoyODN/CaP@LDL, TRAIL dramatically inhibited hepatic tumor growth in a xenograft model and induced significant tumor apoptosis in vivo. Conclusion. These results suggested that CaP@LDL-mediated STAT3-decoy ODN delivery might be a promising new strategy for reversing TRAIL resistance in hepatocellular carcinoma therapy.

[Self-assembly and in vitro and in vivo evaluation of spherical crystallized interferon for sustained delivery].

It is a challenging and important project to prolong the in vivo half life of protein and peptide drugs by physicochemical methods without new molecular entities generation. Protein crystallization provides a new strategy for improving the stability and in vivo delivery of these drugs. We show here that recombinant human interferon-alpha (rhIFN) can form spherical crystals. The physical and chemical features of the crystals were characterized, and drug dissolution was determined in vitro. The pharmacokinetics of crystallized interferon after sc injection in rabbit at 1.5 x 10(7) U x kg(-1) was compared to that of soluble form. The crystals were characterized as mono-dispersed spheres, with yield of > 80%, mean diameter size of about 16 microm and crystallinity of 23.2%. The in vitro dissolution behavior of crystallized rhIFN was featured as low initial burst release (21% within the first 2 h) and prolonged cumulative dissolution time up to 72 h without biological potency lost. After sc administration of soluble and crystallized interferon in rabbits, the peak time (T(max)) and half life (t1/2) were prolonged from (1.80 +/- 0.45) h and (1.35 +/- 0.35) h to (13.20 +/- 2.68) h and (10.68 +/- 1.97) h, respectively. The corresponding peak concentration decreased from (1 411.10 +/- 575.28) U x mL(-1) to (721.37 +/- 206.55) U x mL(-1). PK/PD analysis indicated that (96.87 +/- 20.30) % of relative bioavailability was obtained. The research results of this work will provide important academic value and application prospect for improving clinical therapeutic effect and development of biomacromolecules delivery system for protein and peptide drugs.

Metal ions guided self-assembly of therapeutic proteins for controllable release: from random to ordered aggregation.

PURPOSE: To make a comparative study on sustained delivery performance of rhIFN with random amorphous and spherical crystal-like ordered self-assemblies. METHODS: The rhIFN self-assemblies were identified in batch crystallization mode. Physico-chemical characteristics were compared, including morphology, XRD, FTIR, CD, biological potency, the dissolution behaviors in vitro and plasma pharmacokinetics in vivo. Moreover, molecular simulation was performed to better understand their binding site and mode. RESULTS: Here, we suggest that random amorphous and spherical ordered self-assemblies allow for long action without new molecular entities generation or carriers employed. By manipulating supersaturation, the ordered aggregates were self-organized at high concentration of Zn(II) (>100 mM) in pH 5.5-6.0, which was the first time that spherical semi-crystals of rhIFN can act as a depot source for the sustained delivery of biologically active proteins. The secondary structure and biological potency of rhIFN were unchanged after aggregation. Compared with that of the native rhIFN, both self-assemblies exhibited slower absorption and extended elimination profiles after s.c. administration, which were characterized as 4.75 ± 0.82 h and 10.58 ± 1.86 h of terminal half-life for random amorphous and spherical ordered self-assemblies, respectively. CONCLUSIONS: The work described here demonstrates the possibility of self-assemblies of biomacromolecules for controllable release application of therapeutic proteins.

Polycationic peptide guided spherical ordered self-assembly of biomacromolecules.

Achieving effective controllable delivery of therapeutic biomacromolecules for long action without new molecular entities generation or carriers employed offers a promising alternative and significant clinical benefit. We show here that recombinant human interferon-alpha (rhIFN) can form a three dimensional ordered structure that is featured by spherical semi-crystalline through molecular self-assembly directed by a polycationic short peptide. The phase diagrams for self-assembly were constructed to identify the optimal regions for nucleation and ordered growth, and which were followed by the physico-chemical characterization of the ordered self-assemblies, including morphology, particle size, X-ray diffraction, circular dichroism and biological potency evaluations. With varied molar ratio of the two composed biomacromolecules, the dissolution behaviors of the self-assemblies could be manipulated in vitro and in vivo. The plasma pharmacokinetics suggested that s.c. administration of self-assemblies at the specified relative proportion of rhIFN to polycationic peptide offered a significant prolonged duration time of rhIFN blood levels up to seven days. Moreover, molecular simulation was performed to better understand their binding site and mode. The work described here demonstrates the possibility of spherical ordered self-assembly of biomacromolecules for controllable delivery application of therapeutic proteins.