Table 4

Summary of studies using resorbable membranes for long bone defects in small animal models

Author/Year [ref]

Animal model

Type of membrane

Study design

Assessment of bone regeneration





Rats tibia

decalcified cortical osseous membrane [GenDerm(®)]

To study the effect of using lyophilized bovine bone (GenOx(®) organic matrix) with (or without) GBR (using a decalcified cortical osseous membrane [GenDerm(®)])

Surgically created critical-size defects

group I (control)

group II (defect filled with GenOx(®)

group III (defect covered by GenDerm(®)

group IV (defect filled with GenOx(®) and covered by GenDerm(®)

At 30 or 90 days

Histological and histomorphometrical

Superior bone healing in all groups compared to control group.

Group IV showed evidence of more advanced healing at 30 and 90 days compared with the other groups.




Rabbits tibia

electrospun PLLA nanofibrous membrane +/- collagen

Large bony defects

Three groups: a nanofiber-reinforced bilayer membrane, a nanofibrous membrane, or a collagenous membrane alone

At three and six weeks Radiological and histological

Bilayer membrane group had more bony tissue formation at thre weeks. At six weeks, only the bilayer membrane-treated bone defects displayed better regeneration of cortical bone tissue. Other groups: defects filled with spongy bone-like tissue.




Rabbits femur


A 5 mm in diameter defect created transcutaneously

Group I: control, left to heal spontaneously

Group II (BOC+BG): filled with Bio-Oss Collagen and Bio Gide Perio membrane

Group III: BOC and platelet-rich plasma

At one and three months


Greater number of bone trabeculas after implantation in groups II and III compared to control.




Rabbits tibia

calcium alginate film (CAF) versus collagen or no membrane

Circular bone 5 mm diameter defects

CAF versus collagen versus no membranes

At one, two, four, six, and eight weeks

Gross evaluation, radiological, histological, immuno-histochemical, and an image pattern analysis system

CAF induced dense bone formation, whereas CM induced less new bone, and the blank control sites even less.




Rabbit fibula

chitosan membrane

5 mm defect filled with a porous nano-hydroxyapatite-chitosan composite multilayer scaffold

At 12 weeks

Radiological and histological

Composite membranes are implanted into a fibular defect to evaluate the osteoconductivity and the efficacy as a barrier to fibrous tissue ingrowth: affluent blood vessels and bone formation found in the center of the scaffold and little fibrous tissue noted within the defect.




Rats Femur

decalcified cortical osseous membrane [GenDerms]) +/- Laser irradiation

Surgical bone defects, five groups:

Group I (control); Group II (Gen-ox: lyophilized bovine bone organic matrix)

Group III (Gen-ox + Laser);

Group IV (Gen-ox + Gen-derm);

Group V (Gen-ox + Gen-derm + Laser)

At 15, 21, and 30 days.

Histological assessment.

Improved amount of collagen fibers at early stages of the bone healing (15 days) and increased amount of well organized bone trabeculae at 30 days on irradiated animals compared to non irradiated ones.




Rabbits radius

two types:

- non-resorbable ethyl cellulose membrane

(EC, N-type, Hercules Inc., Delaware)

- resorbable chitosan

membrane (CH, poly(D-glucosamine), Aldrich)

1 cm segmental radial defect

(2.5 times the radial bone diameter)


Every two weeks for an eight-week period.

Bone density in the different osteotomy


Histological evaluation (scoring system)

Four rabbits at two week intervals

EC group: an increase in the new bone density was apparent in all quadrants during the first four weeks, followed by a sharp decline in bone density.

CH group: different biological behavior, lesser increment in bone density in the first four weeks but continued throughout the eight weeks.

Possible cause: degradation of membrane products and foreign body reaction.

Based on histological findings: EC membranes are better osteoinducers.

Radiological findings: CH membranes are better osteoconductors.




Rats femur

fresh, morselized porcine small intestine submucosa (SIS) used as preformed tubular SIS grafts

Critical length segmental defects

four groups: unfilled or filled with morselized cancellous bone, or spanned with intramedullary tubes or periosteal sleeves fabricated from SIS

Radiological (biweekly)

At 12 weeks histological, and mechanical testing

New bone formation in all defects treated with cancellous bone. Fibrous tissue and no bone formation in defects left unfilled or treated with SIS

SIS persisted at twelve weeks.

Cellular response to SIS: mild mononuclear infiltrate in the loose or delaminated superficial layers of the tubes and sleeves, with few cells in the deeper layers.

The ability of SIS to support or stimulate growth of bone across a critical length segmental bone defect is doubted.




Rabbit radii

poly(L/DL-lactide) membrane or sponge


Segmental defect, four groups:

I: untreated + plaster,

II: plate fixation

III: membrane + plate fixation

IV: sponge + plate fixation


At eight weeks histological

Group I + II: no healing

Group III: healing

Group IV: more abundant healing than III




Rat tibia

alginate membrane (bioabsorbable)

Calcium chloride aqueous solution dropped into the bone defect, which is filled with sodium alginate aqueous solution.


Evaluation of short-term biocompatibility of alginate membrane. The healing process in bone defects covered with an alginate membrane was delayed in comparison with that of controls; however, the defect was restored to nearly original condition.

In contrast, in the controls, bone defect repairs exhibited partitioning as a result of connective tissue involvement.

A relation between the sodium alginate concentration and the rate of absorption of the sodium alginate membrane was noted.

No inflammatory response around the alginate membrane.




Rats tibia



e-PTFE groups

control groups (without membrane)


At six, eight, or ten days using immunohistochemistry and confocal laser scanning microscopy to investigate new bone mineralization

The bone occupation ratio increased day by day, but the experimental groups had significantly higher ratios than control groups (without membrane) at each of the time periods. More rapid mineralization in the experimental groups vrsus controls.

GBR accelerates the migration of osteogenic cells, the formation of new bone, and mineralization in the defect created by the e-PTFE membrane.




Rabbits radius



10 mm diaphyseal defects

(both sides: test and control)

Test side: bone marrow ingrowth into the defects was hindered or delayed (plugging the opening of the cut bone ends with gutta-percha points; plugging with Gelfoam; or by removing the bone marrow by flushing with saline), in all defects: an ePTFE membrane, shaped as a tube

Regular radiological

At four to five months, histological

Any attempts to delay or prevent bone marrow ingrowth into the defects retard regeneration of segmental long-bone defects.






+/- resorbable collagen membrane

(bovine Achilles tendon collagen Type I)

Ten hydroxyapatite-coated titanium fixtures inserted within a created cortical defect, covered with a resorbable membrane

Control: no membrane

At 60 days

Tensile shear-stress at break testing and histological

Lower performance without membrane

Neoformed cortical bone present cervically around implant was much thicker when a collagen membrane was used.




Rabbits radius

poly(L/D-lactide) and poly(L/DL-lactide) membranes (bioabsorbable)

10 mm diaphyseal segmental defects

- membranes from poly(L/D-lactide)

- poly(L/DL-lactide)

to determine whether chemical composition of the membrane affected the bone healing in the defect.

Control: previous study with same animal model and similar defects not covered with membranes or covered with poly(L-lactide) membranes

Radiological at two, four, six, and eight weeks

Histological at 3, 6 and 12 months

At one year: complete bone regeneration in the defects covered with the poly(L/D-lactide) membrane, only one animal with no regeneration and one animal with pseudarthrosis.

Complete bone regeneration in all animals for the poly(L/DL-lactide) membrane (one animal died during surgery).

The quality of the interface between the new bone and the membrane seemed to be affected by the chemical structure of the polylactides used for membranes preparation. The differences in chemical composition of the polylactide membranes did not have an evident effect on the bone regeneration process in segmental defects of the rabbit radii.




Rats tibia

alginate membrane

3 mm × 10 mm bicortical bone defect filled with 0.5, 1.0, or 1.5% Na-Alg aqueous solution, then 3% calcium chloride aqueous solution was dropped on the Na-Alg solution to form an alginate membrane.

four groups: (a) control group (no solutions)

(b) alginate membrane with 0.5% Na-Alg solution

(c) alginate membrane with 1.0% Na-Alg solution

(d) alginate membrane with 1.5% Na-Alg solution


At four weeks

Control group: bone defect filled with connective tissue.

0.5% Na-Alg solution: part of the alginate membrane had disappeared and connective tissue had begun to grow in the bone defect.

1.0 or 1.5% Na-Alg solution: the alginate membrane prevented any ingress of connective tissue to the bone defect, and the bone defect was reconstructed with new bone. At this stage, the alginate membrane still was observed, and the amount of unabsorbed alginate was larger for higher concentrations of Na-Alg aqueous solution. No inflammatory response was observed around the alginate membrane.




Rats radius

small intestinal submucosa (SIS)

The defect was either left unfilled or implanted with SIS, demineralized cortical bone (DMCB), or ovalbumin.

Radiographically and histologically after 3, 6, 12, and 24 weeks.

Tissue remodelling within the defect was evident by week three in SIS- and DMCB-treated rats. Filling was characterized initially by infiltration of mononuclear cells and extracellular material in SIS-implanted rats and multifocal remodelling bone particles and cartilage formation in DMCB-implanted rats. Cartilage was observed as early as three weeks and bone as early as six weeks in SIS-implanted rats. Filling of the defect arose from multiple foci in DMCB-implanted rats, but was contiguous with and parallel to the ulnar shaft in SIS-implanted rats, suggesting that defect repair by SIS may be conductive rather than inductive. Rats in which the defect was left unfilled demonstrated slow but progressive filling of the defect, characterized by mononuclear cell infiltrates and fibrous extracellular material. SIS facilitated rapid filling of a long-bone defect.




Minipigs radius

polymer membranes:

poly(L/DL-lactide) and poly(D-lactide)


2.5 to 3 cm mid-diaphyseal defect

five groups: (a) poly(L/DL-lactide),

(b) poly(L/DL-lactide)-CaCO3,

(c) poly(D-lactide),

(d) poly(D-lactide)-CaCO3,

(e) untreated defect

Ulna left intact and no adjunctive internal or external fixation

Radiological (biweekly)

At 12 weeks, histologic and microradiographic evaluation

The bone defects covered with membranes were completely reconstituted by six to eight weeks. Untreated defects healed with less bone formation and in a more disorganized pattern. Histologic evaluation of the implants demonstrated that the entire lumen of the implant was filled with bone, with some periosteal bone formation occurring on the outer surface of the membrane. Direct apposition of bone onto the membrane surface or minimal fibrous tissue interposition between membrane and new bone. No foreign body or adverse reaction to the membrane.




Rabbits radius

silicone membrane

10-mm defect on radius silicone membrane sutured as a tube

10-mm defects were also produced on the control sides.

At 12 weeks radiological, three-point bending test, and histological

By the 12th week, seven of ten experimental sides were healed, two were healed with a connective cartilage zone, and one was not healed. None of the control was healed but the defect was occupied by soft tissue.




Rabbits radius

poly(L-lactide) membranes of various pore sizes

(microporous, medium pore size (10 to 20 microns), and large pore size (20 to 200 microns)


10 mm diaphyseal defect

No internal fixation (assumption that the intact ulna splints the radius adequately)

Radiological at two and four weeks and six months

Bone regeneration in the majority of cases, regardless of pore size.

Some differences in the intensity of the bone regeneration process. At two weeks, bone formation seen in all animals, but at six months five rabbits of five, four rabbits of five, and three rabbits of five implanted respectively with microporous, medium pore-size and large pore-size membrane showed complete regeneration of the defect.




Rabbits radius

ePTFE membrane


7 to 10 mm segmental diaphyseal defects

Study group: membrane formed as a tube

Control: contralateral side with no membrane

Radiological (obtained repeatedly) and histological at 13 or 27 weeks

Control group: some early subperiosteal callus formation and non-union of the defects at six weeks.

Study group: subperiosteal bone formation at the bone ends first observed at two weeks. At nine weeks, a thin cortical bone bridged the defect along the inner surface of the membrane.

Histology: an interrupted line of thin, cortical bone was observed along the inner surface of the barrier membrane. Fatty bone marrow occupied the central and largest volume of the defect.

Farso Nielsen



Rabbits radius

polyurethane membrane (bioabsorbable)

1 cm segmental, osteoperiosteal defects

Study group: membrane formed as a tube

versus untreated control

At five weeks

Radiological and histological

Controls: 90% non-union

Membrane-treated defects: all healed by forming callus external to the membrane fusing the bone fragments. Loose connective tissue was predominant in the bone gap underneath the membrane.

Dimitriou et al. BMC Medicine 2012 10:81   doi:10.1186/1741-7015-10-81

Open Data