Acidic Gelatin Research Articles

Gelatin based bio-films prepared from grey triggerfish’ skin influenced by enzymatic pretreatment

Gelatins from grey triggerfish skin were extracted with different methods. The treatment by pepsin (PG) improved the yield of extraction when compared with untreated gelatin (UG) and acidic gelatin (AG). The outputs of gelatins AG, UG and PG, obtained respectively, with acitic acid, glycine buffer and glycine buffer added with 5U of pepsin/g of the skin beforehand treated by alkali, were 6.9%, 7.9% and 9.7%, respectively. The enzymatic treatment of the alkali-pretreated skin of grey triggerfish altered the electrophoresis profile, biophysical, gellification, rheological and thermal properties of the prepared gelatins extracted under acidic condition. However, the untreated gelatin obtained without pepsin exhibited the highest transition and enthaply temperatures. In addition, the properties of the prepared films were interconnected to their microstructure as demonstrated by scanning electron microscopy. Furthermore, films with PG and UG had a regular surface and a more condensed structure, whereas films prepared with AG had rougher surface.

Production of electrospun gelatin nanofibers: an optimization study by using Taguchi’s methodology

Electrospinning of gelatin from its solution with a non-toxic solvent is not easy. It certainly requires understanding the effects of critical parameters during electrospinning. In this paper, the first aim was to understand how the morphology and diameter of fibers produced from a solution of gelatin in acetic acid (HAc) were affected by solvent concentration and process parameters (flow-rate, applied voltage, distance between the needle-tip and collector) by using Taguchi’s orthogonal design. For this purpose, the optimum levels of factors were determined as follows: voltage 18 kV, flow rate 15 µl min−1, distance 12.5 cm, and HAc concentration 20% in order to obtain the thinnest nanofiber. Secondly, this combination was further validated by conducting a confirmatory experiment using five different gelatin concentrations to observe the effect of concentration. The average diameters of fibers with 24 and 28% gelatin concentrations were found as similar to the optimum conditions estimated, proving the applicability of Taguchi’s method for electrospinning optimization.

Enhancing mechanical strength of hydrogels via IPN structure

ABSTRACTIn this investigation, polyacrylamide (PAAm) as the flexible network is introduced to enhance the mechanical strength of hyaluronic acid–gelatin (HA–Gel) hydrogels by interpenetrating polymer network (IPN). The structure, mechanical property, and rheology property of the IPN hydrogels are investigated. It is found that the compressive strength of the HA–Gel/PAAm IPN hydrogels has increased five times higher than that of HA–Gel hydrogels. Rheological test demonstrates that elastic moduli (G′) and viscous moduli (G″) of HA–Gel/PAAm IPN hydrogels increase 100 times higher than those of HA–Gel hydrogels. Moreover, the HA–Gel hydrogels are fractured under the low compressive stress, whereas HA–Gel/PAAm IPN hydrogels are not broken under the high compressive stress. It is envisioned that the IPN hydrogels will be an effective approach to enhance the mechanical strength and broaden the range of hydrogels' applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44503.

Higher Ratios of Hyaluronic Acid Enhance Chondrogenic Differentiation of Human MSCs in a Hyaluronic Acid-Gelatin Composite Scaffold.

Mesenchymal stem cells (MSCs) seeded on specific carrier materials are a promising source for the repair of traumatic cartilage injuries. The best supportive carrier material has not yet been determined. As natural components of cartilage’s extracellular matrix, hyaluronic acid and collagen are the focus of biomaterial research. In order to optimize chondrogenic support, we investigated three different scaffold compositions of a hyaluronic acid (HA)-gelatin based biomaterial. Methods: Human MSCs (hMSCs) were seeded under vacuum on composite scaffolds of three different HA-gelatin ratios and cultured in chondrogenic medium for 21 days. Cell-scaffold constructs were assessed at different time points for cell viability, gene expression patterns, production of cartilage-specific extracellular matrix (ECM) and for (immuno-)histological appearance. The intrinsic transforming growth factor beta (TGF-beta) uptake of empty scaffolds was evaluated by determination of the TGF-beta concentrations in the medium over time. Results: No significant differences were found for cell seeding densities and cell viability. hMSCs seeded on scaffolds with higher ratios of HA showed better cartilage-like differentiation in all evaluated parameters. TGF-beta uptake did not differ between empty scaffolds. Conclusion: Higher ratios of HA support the chondrogenic differentiation of hMSCs seeded on a HA-gelatin composite scaffold.

In Vitro Testing of Scaffolds for Mesenchymal Stem Cell-Based Meniscus Tissue Engineering-Introducing a New Biocompatibility Scoring System.

A combination of mesenchymal stem cells (MSCs) and scaffolds seems to be a promising approach for meniscus repair. To facilitate the search for an appropriate scaffold material a reliable and objective in vitro testing system is essential. This paper introduces a new scoring for this purpose and analyzes a hyaluronic acid (HA) gelatin composite scaffold and a polyurethane scaffold in combination with MSCs for tissue engineering of meniscus. The pore quality and interconnectivity of pores of a HA gelatin composite scaffold and a polyurethane scaffold were analyzed by surface photography and Berliner-Blau-BSA-solution vacuum filling. Further the two scaffold materials were vacuum-filled with human MSCs and analyzed by histology and immunohistochemistry after 21 days in chondrogenic media to determine cell distribution and cell survival as well as proteoglycan production, collagen type I and II content. The polyurethane scaffold showed better results than the hyaluronic acid gelatin composite scaffold, with signs of central necrosis in the HA gelatin composite scaffolds. The polyurethane scaffold showed good porosity, excellent pore interconnectivity, good cell distribution and cell survival, as well as an extensive content of proteoglycans and collagen type II. The polyurethane scaffold seems to be a promising biomaterial for a mesenchymal stem cell-based tissue engineering approach for meniscal repair. The new score could be applied as a new standard for in vitro scaffold testing.

Effect of carbodiimide-derivatized hyaluronic acid gelatin on preventing postsurgical intra-abdominal adhesion formation and promoting healing in a rat model.

Adhesions often occur after abdominal surgery. It could cause chronic pelvic pain, intestinal obstruction, and infertility. A hydrogel biomaterial, carbodiimide-derivatized hyaluronic acid gelatin (cd-HA gelatin), has been successfully used to reduce adhesion formation after flexor tendon grafting. This study investigated the efficacy of cd-HA gelatin in preventing postsurgical peritoneal adhesions in a rat model. The surgical traumas were created on the underlying muscle of the abdominal wall and the serosal layer of the cecum. The wounds were covered with or without cd-HA gelatin. Animals were euthanized at day 14 after surgery. Adhesion formation was assessed with adhesion degree and adhesion breaking strength. The healing of abdominal wall was evaluated with biomechanical testing and histological analysis. The adhesions occurred in all rats (n = 12) without cd-HA gelatin treatment. The application of cd-HA gelatin significantly reduced the adhesion rate from 100% to 58%. The decrease of adhesion breaking strength also manifested that cd-HA gelatin could reduce postsurgical intra-abdominal adhesion formation. Moreover, it was found that cd-HA gelatin was a safe material and could promote tissue healing. The cd-HA gelatin hydrogel could reduce the formation of intra-abdominal adhesions without adversely effects on wound healing.

Proapoptotic effect of control-released basic fibroblast growth factor on skin wound healing in a diabetic mouse model.

The ability of basic fibroblast growth factor (bFGF) to improve wound healing is attenuated by its short half-life in free form. This study aimed to enhance skin wound healing in a diabetes mouse model while concomitantly decreasing scar formation using control-released bFGF together with acidic gelatin hydrogel microspheres (AGHMs). Bilateral full-thickness wounds (10 mm in diameter) were made on the backs of db/db mice. Forty-five mice were divided into three groups, and the base of the wound under the panniculus carnosus and the wound periphery were injected with phosphate-buffered saline (300 μL) containing (1) control-released bFGF (50 μg), (2) control-released bFGF (20 μg), or (3) AGHMs alone. The size of the wound area was recorded on each postoperative day (POD). Mice were sacrificed on postoperative day 4, 7, 10, 14, and 28, and skin wound specimens were obtained to assess the endothelium/angiogenesis index via cluster of differentiation 31 immunohistochemistry, the proliferation index via Ki-67 immunohistochemistry, and the myofibroblast and fibroblast apoptosis indices by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and alpha-smooth muscle actin or vimentin staining, respectively. Epithelialization rates and indices of proliferation and myofibroblast/fibroblast apoptosis were higher in the bFGF groups than in the AGHM group, mainly within 2 weeks of injury. No dose-effect relationship was found for control-released bFGF, although the actions of 50 μg bFGF seemed to last longer than those of 20 μg bFGF. Therefore, control-released bFGF may accelerate diabetic skin wound healing and induce myofibroblast/fibroblast apoptosis, thereby reducing scar formation.

Doxorubicin-loaded microgels composed of cinnamic acid–gelatin conjugate and cinnamic acid–Pluronic F127 conjugate

Microgels were prepared by cinnamic acid–gelatin (type B) conjugate (CA-GelB) and cinnamic acid–Pluronic F127 conjugate (CA-Plur). 1H NMR confirmed that CA was conjugated to gelatin and the gelatin to CA residue molar ratio was estimated to be 1:4.7 by a colorimetric method. CA-Plur of which the CA residue to Plur molar ratio was 1.2:1 was used as a thermo-sensitive polymer. The CA residues of CA-Plur/CA-GelB mixture were readily photo-dimerized to form microgels by UV irradiation. The isoelectric point of the microgel was found to be pH 5.8 and the hydrodynamic diameter decreased when the suspension temperature increased. The microgel could hardly retard the release of doxorubicin (DOX) at pH 3.0 and pH 5.0, but it could suppress and control the release at pH 7.4 possibly due to electrostatic attraction. Meanwhile, the release of DOX at pH 7.4 was less suppressed when the medium temperature was higher, possibly because of thermal thinning of Pluronic chain layer.

Facial nerve regeneration using basic fibroblast growth factor-impregnated gelatin microspheres in a rat model.

Basic fibroblast growth factor (bFGF) plays a crucial role in the regeneration of peripheral nerve defects by affecting nerve cells, Schwann cells and fibroblasts, and by promoting axon outgrowth from the proximal nerve stump. However, the use of exogenous bFGF for in vivo regeneration of the peripheral nerves is limited by its short in vivo half-life. In this study, a drug delivery system for bFGF was developed that uses acidic gelatin hydrogel, which sustainably released bFGF in vivo over several weeks; its ability to promote peripheral nerve regeneration was also examined. In 8-week-old Lewis rats, 7-mm gaps were made in the buccal branch of the left facial nerve. Acidic gelatin hydrogel microspheres (10 µl) with or without bFGF (50 µg) were infused into a 10 mm silicone tube using a micropipette, and the silicone tube was then implanted into the gap. A 1-mm long nerve stump was inserted into each end of the tube. Histological examination at 7 weeks after implantation revealed (1) a significantly increased rate of nerve regeneration, (2) inducement of a number of regenerating nerve axons, and (3) a better degree of maturation of nerve axons in the bFGF microsphere group than that in the bFGF-free microsphere group. Copyright © 2014 John Wiley & Sons, Ltd.

An In Vivo Study of Composite Microgels Based on Hyaluronic Acid and Gelatin for the Reconstruction of Surgically Injured Rat Vocal Folds

PURPOSE The objective of this study was to investigate local injection with a hierarchically microstructured hyaluronic acid-gelatin (HA-Ge) hydrogel for the treatment of acute vocal fold injury using a rat model. METHOD Vocal fold stripping was performed unilaterally in 108 Sprague-Dawley rats. A volume of 25 μl saline (placebo controls), HA-bulk, or HA-Ge hydrogel was injected into the lamina propria (LP) 5 days after surgery. The vocal folds were harvested at 3, 14, and 28 days after injection and analyzed using hematoxylin and eosin staining and immunohistochemistry staining for macrophages, myofibroblasts, elastin, collagen type I, and collagen type III. RESULTS The macrophage count was statistically significantly lower in the HA-Ge group than in the saline group (p < .05) at Day 28. Results suggested that the HA-Ge injection did not induce inflammatory or rejection response. Myofibroblast counts and elastin were statistically insignificant across treatment groups at all time points. Increased elastin deposition was qualitatively observed in both HA groups from Day 3 to Day 28, and not in the saline group. Significantly more elastin was observed in the HA-bulk group than in the uninjured group at Day 28. Significantly more collagen type I was observed in the HA-bulk and HA-Ge groups than in the saline group (p < .05) at Day 28. The collagen type I concentration in the HA-Ge and saline groups was found to be comparable to that in the uninjured controls at Day 28. The concentration of collagen type III in all treatment groups was similar to that in uninjured controls at Day 28. CONCLUSION Local HA-Ge and HA-bulk injections for acute injured vocal folds were biocompatible and did not induce adverse response.

Preclinical Efficacy of Slow-Release bFGF in Ischemia-Reperfusion Injury in a Dorsal Island Skin Flap Model

The effect of slow-release basic fibroblast growth factor (bFGF) on ischemia-reperfusion injury was examined using an island skin flap model in rats. Paired rectangular island skin flaps were elevated on the dorsum of 30 Fischer rats. The flaps were subjected to 6 hours of ischemia. Before reperfusion the flaps were injected with acidic gelatin hydrogel microspheres + phosphate-buffered saline (PBS) (group I), 20 μg slow-release bFGF + PBS (group II), 50 μg slow-release bFGF + PBS (group III), and 150 μg slow-release bFGF + PBS (group IV). The mean percent flap survival area and the average number of vessels detected by microangiography were significantly higher in group IV (p < 0.05) than in groups I, II, and III. The immunohistochemical staining for vasculogenic growth factors was quantitatively higher in group IV (p < 0.01). In conclusion, slow-release bFGF prevents ischemia-reperfusion injury by upregulating the secretion of vasculogenic growth factors.

Fabrication and in vitro evaluations with osteoblast-like MG-63 cells of porous hyaluronic acid-gelatin blend scaffold for bone tissue engineering applications

In this study, hyaluronic acid–gelatin (HyA–Gel) scaffolds were prepared with HyA:Gel ratios of 15:85, 50:50, and 85:15 with the goal of obtaining a porous biocompatible scaffold for bone tissue engineering applications. Scanning electron microscopy and Fourier-transform infrared spectroscopy were done to characterize the morphological orientations of the scaffolds. The biocomposite structure was highly porous and the pores in the scaffolds were interconnected. The compressive strength of the scaffold was 7.39 ± 0.2 MPa for the HyA–Gel when fabricated at a ratio of 15:85. To assess the biocompatibility and cell behavior on the HyA–Gel biocomposite, the proliferation of MG-63 osteoblast cell on the scaffolds was examined using the MTT assay, optical microscopy, and confocal microscopy. Collagen type I and osteopontin expression of cells cultured on the scaffolds were examined using immunoblotting. The scaffolds fabricated with a 15:85—HyA:Gel ratio showed excellent biocompatibility, good mechanical properties, and high porosity, which suggest that the highly porous scaffold holds great promise for use in bone tissue engineering applications.

In situ forming hydrogels composed of oxidized high molecular weight hyaluronic acid and gelatin for nucleus pulposus regeneration

Encapsulation of nucleus pulposus (NP) cells within in situ forming hydrogels is a novel biological treatment for early stage intervertebral disc degeneration. The procedure aims to prolong the life of the degenerating discs and to regenerate damaged tissue. In this study we developed an injectable oxidized hyaluronic acid–gelatin–adipic acid dihydrazide (oxi-HAG–ADH) hydrogel. High molecular weight (1900kDa) hyaluronic acid was crosslinked with various concentrations of gelatin to synthesize the hydrogels and their viscoelastic properties were analyzed. Interactions between the hydrogels, NP cells, and the extracellular matrix (ECM) were also evaluated, as were the effects of the hydrogels on NP cell gene expression. The hydrogels possess several clinical advantages, including sterilizability, low viscosity for injection, and ease of use. The viscoelastic properties of the hydrogels were similar to native tissue, as reflected in the complex shear modulus (∼11–14kPa for hydrogels, 11.3kPa for native NP). Cultured NP cells not only attached to the hydrogels but also survived, proliferated, and maintained their round morphology. Importantly, we found that hydrogels increased NP cell expression of several crucial ECM-related genes, such as COL2A1, AGN, SOX-9, and HIF-1A.

An Injectable Nucleus Pulposus Implant Restores Compressive Range of Motion in the Ovine Disc

Investigation of injectable nucleus pulposus (NP) implant. To assess the ability of a recently developed injectable hydrogel implant to restore nondegenerative disc mechanics through support of NP functional mechanics. Although surgical intervention for low back pain is effective for some patients, treated discs undergo altered biomechanics and adjacent levels are at increased risk for accelerated degeneration. One potential treatment as an alternative to surgery for degenerated disc includes the percutaneous delivery of agents to support NP functional mechanics. The implants are delivered in a minimally invasive fashion, potentially on an outpatient basis, and do not preclude later surgical options. One of the challenges in designing such implants includes the need to match key NP mechanical behavior and mimic the role of native nondegenerate NP in spinal motion. The oxidized hyaluronic acid gelatin implant material was prepared. In vitro mechanical testing was performed in mature ovine bone-disc-bone units in 3 stages: intact, discectomy, and implantation versus sham. Tested samples were cut axially for qualitative structural observations. Discectomy increased axial range of motion (ROM) significantly compared with intact. Hydrogel implantation reduced ROM 17% (P < 0.05) compared with discectomy and returned ROM to intact levels (ROM intact 0.71 mm, discectomy 0.87 mm, postimplantation 0.72 mm). Although ROM for the hydrogel implant group was statistically unchanged compared with the intact disc, ROM for sham discs, which received a discectomy and no implant, was significantly increased compared with intact. The compression and tension stiffness were decreased with discectomy and remained unchanged for both implant and sham groups as expected because the annulus fibrosus was not repaired. Gross morphology images confirmed no ejection of NP implant. An injectable implant that mimics nondegenerate NP has the potential to return motion segment ROM to normal subsequent to injury.

Flow-induced phase behaviour and structure development in aqueous emulsion of associative biopolymers

A rheo-optical methodology, based on small angle light scattering and transmitted light intensity measurements, has been used to perform an in-situ and time-resolved investigation on the effect of simple shear flow on associative phase separation, morphology development, and the interfacial tension, using a water–acid gelatin–gum arabic system as a model. It is shown that above a critical shear rate, shear-induced mixing occurs at 45 °C at the length scales probed by the laser light. Shift of the phase diagram at a fixed shear rate (100 s −1) was determined. When flow is stopped after homogenization, phase separation occurs almost instantaneously. When subsequently applying a low shear rate, the structure coarsens due to coalescence of the dispersed droplets. Shear-induced mixing does not occur at 35 °C probably due to the sharp increase of the interfacial tension from 5.5·10 −5 N/m to 9.0·10 −5 N/m.

Mesoporous silicas prepared from sodium silicate using gelatin templating

ABSTRACTGelatin was employed as a templating agent for the preparation of mesoporous silica materials starting from sodium silicate solutions using a sol‐gel method. The silicate anions were first transformed into silicic acid by passing the solution through an H+ ion‐exchange resin, then mixed with acidic gelatin solution prior to adjustment of the pH to approximately 9–10. Gelatin was removed by solvothermal Soxhlet extraction to form pores. We show that gelatin can serve as a structure‐directing agent resulting in silica structures with pores spanning a range of 3–12 nm depending on gelatin concentration. Increasing gelatin concentration resulted in a larger pore size and a wider pore‐size distribution. This dependence was also observed for the surface area and pore volume but only at low gelatin concentration (&lt;0.4 wt%). The surface area and the pore volume tended to decrease with increasing gelatin concentration at high gelatin concentration (&gt;0.4 wt%). Mesoporous silica with a high specific surface area (426.6 m2 g−1), high pore volume (0.9 cm3 g−1) and large pore diameter (8.4 nm) was obtained at a gelatin concentration of 0.41 wt%. © 2011 Curtin University of Technology and John Wiley &amp; Sons, Ltd.

Augmented angiogenesis in adventitia promotes growth of atherosclerotic plaque in apolipoprotein E-deficient mice

ObjectiveAccumulating evidence suggests that exaggerated formation of vasa vasorum (VV) plays an important role in the pathogenesis of atherosclerosis. However, it remains unclear whether augmented angiogenesis in the adventitia could promote hyperlipidemia-induced atherosclerotic lesion formation. Methods and resultsFirst, we analyzed the time course of VV development in apolipoprotein E-deficient (ApoE−/−) mice. VV proliferation was observed only after atherosclerotic lesion formation. Next, we investigated whether forced perivascular angiogenesis could promote plaque progression. Basic fibroblast growth factor (bFGF) (100μg/body) incorporated in acid gelatin hydrogel microspheres (AGHM) (bFGF+AGHM group, n=10), AGHM alone (AGHM group, n=7), or PBS (control group, n=8) was administered into the periaortic area of the retroperitoneal space in 10- to 11-week-old male ApoE−/− mice. At 13 weeks after the operation, lesions were significantly larger in the bFGF+AGHM group than in others (bFGF+AGHM: 3.4±0.7×104μm2; AGHM: 0.1±0.1×104μm2; control: 0μm2; p<0.0001), which was associated with increased neovascularization in the adventitia. The number of adventitial capillaries correlated with plaque size (r=0.69, p<0.0001). In the bFGF+AGHM group, an increase in the number of VV and accumulation of Mac3-positive macrophages were observed prior to atherosclerotic lesion formation. ConclusionsOur findings demonstrated that local administration of bFGF in the adventitia induced development of VV and accelerated plaque progression in ApoE−/− mice, supporting the notion that VV formation plays a crucial role in the pathogenesis of atherosclerosis.

Neovascularization by bFGF releasing hyaluronic acid–gelatin microspheres: in vitro and in vivo studies

Therapeutic angiogenesis with angiogenic growth factors has been described as a promising approach for tissue engineering, wound healing, and for treating ischemic tissues. Here, we assessed the merit of heparin-entrapped hyaluronic acid–gelatin (HA–G) microspheres for the sustained release of recombinant basic fibroblast growth factor (rbFGF) to promote localized neovascularization. HA–G microspheres were prepared by a water-in-oil emulsion method, and the in vitro release kinetics were first examined using three model proteins. Then, bFGF was incorporated into microspheres, and the bioactivity of the in vitro-released rbFGF was tested on human umbilical vein endothelial cell cultures. The ability to promote microvessel growth was assessed in vivo, at the subcutaneous groin fascia of Wistar rats after 3, 7, 14, and 21 days. Histological and morphometrical analysis indicated that heparin-entrapped HA–G microspheres have the capacity to release bioactive rbFGF, leading to localized neovascularization in the rat subcutaneous tissue.

Influence of rhBMP-2 on bone formation and osseointegration in different implant systems after sinus-floor elevation. An in vivo study on sheep

Several studies have reported certain bone morphogenic proteins (BMPs) to have positive effects on bone generation. Although some investigators have studied the effects of human recombinant BMP (rhBMP-2) in sinus augmentation in sheep, none of these studies looked at the placement of implants at the time of sinus augmentation. Furthermore, no literature could be found to report on the impact that different implant systems, as well as the positioning of the implants had on bone formation if rhBMP-2 was utilized in sinus-lift procedures. The aim of this study was to compare sinus augmentation with rhBMP-2 on a poly-d, l-lactic-co-glycolic acid gelatine (PLPG) sponge with sinus augmentation with autologous pelvic cancellous bone in the maxillary sinus during the placement of different dental implants. Nine adult female sheep were submitted to bilateral sinus-floor elevation. In one side (test group) the sinus lift was performed with rhBMP-2 on a PLPG-sponge, while the contralateral side served as the control by using cancellous bone from the iliac crest. Three different implants (Bränemark(®), 3i(®) and Straumann(®)) were inserted either simultaneously with the sinus augmentation or as a two staged procedure 6 weeks later. The animals were sacrificed at 6 and 12 weeks for histological and histomorphometrical evaluations during which bone-to-implant contact (BIC) and bone density (BD) were evaluated. BD and BIC were significantly higher at 12 weeks in the test group if the implants were placed at the time of the sinus lift (p<0.05). No difference was observed between the different implant systems or positions. The use of rhBMP-2 withPLPG-sponge increased BIC as well as BD in the augmented sinuses if compared to autologous bone. Different implant systems and positions of the implants had no effect on BIC or BD.

Detection of growth factor binding to gelatin and heparin using a photonic crystal optical biosensor

Drug–carrier interactions are important to protein controlled release systems to protect the protein from denaturation and ensure properly timed release. A novel photonic crystal biosensor was used to investigate a gelatin–protein controlled release system to determine the amount of protein bound to the carrier at physiological conditions. The Biomolecular Interaction Detection (BIND) system reflects a narrow band of wavelengths when white light is shone incident to the grating. As mass is deposited onto the surface, the peak wavelength value is shifted due to changes in the optical density of the biosensor. The BIND system was used to detect the binding of growth factors onto acidic gelatin, basic gelatin, and heparin on the sensor surface. Through a series of experiments, including functionalizing the sensor, adjusting the ionic strength of the solution, adjusting the substrate concentration, and minimizing non-specific signal, the adsorption of the gelatins and heparin on the sensor was enhanced. The binding interaction of recombinant human transforming growth factor (rhTGF)-β1 and bone morphogenetic protein (rhBMP)-2 with the two types of gelatin and heparin were investigated. The strength of the interaction between rhTGF-β1 and the substrates is in the following order: heparin > acidic gelatin > basic gelatin. RhBMP-2 bound to the substrates but with less intensity than TGF-β1: heparin > basic gelatin > acidic gelatin. This work provides support for the controlled release mechanism through degradation of the gelatin carrier.